BATTERY TESTING AND . '.; WPwMwWm. *SJ ' ■’ )t W;?r w, • ■, 7 77 ^ mt : ".; ■• 7 .; '-[ y 7 - ■ ; • •■• •; ■ " v • f yw®v^4vif;jriW £ w ^ t-"i' The Burling Vocational Series LOOSE LEAF SHOP MANUAL . REPAIR BY BEVERLY B. BURLING, S.B., E.E. One of a Series of Manuals covering Trade Subjects compiled especially for Technical High, Continuation and Trade Schools. my nffy) Property of. The Burling: Vocational Series, B. B. Burling, Editor. LOOSE Return this book on or before the Latest Date stamped below. A charge is made on all overdue books. TT , T T ., U. of I. Library DEC 23 194 1 BATTERY Mar 19 1343 R V A Manual for Techni for Evening Cla Autc BEVERLY Industrial Training for Met Extension Depar Past Supervis M32 The Bruce Publishing Company, Milwaukee, Wis. LOOSE LEAF SHOP MANUAL BATTERY TESTING AND REPAIR A Manual for Technical High Schools, Trade Schools and for Evening Classes in Applied Electricity and Automotive Electricity. BY BEVERLY B. BURLING, S.B., E.E. Industrial Training for Men and Boys, Milwaukee Board of Education, Extension Department, University of Wisconsin, Past Supervisor of Co-operative Education. The Bruce Publishing Company, Milwaukee, Wis. t Iff* i If “ *, i ( j ■ z G 2L I ■ 353 Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair BATTERY TESTING AND REPAIR TABLE OF CONTENTS Title Preface Contents Electrical Symbols Standard Test Report Blank - Definitions of Terms Frequently Used in Battery Work A- 1 — Construction of the Storage Battery. A- 2 — The Conversion of Chemical Into Electrical Energy. A- 3 — The Hydrometer and Thermometer. A- 4 — The Electrolyte. A- 5 — The Voltmeter. A- 6 — The Ammeter. A- 7 — Polarization of Primary Cells. A- 8 — Series and Parallel Combination of Cells. A- 9 — Charging Battery Using Hydrometer for Testing. A-10 — Complete Test of Six Volt Battery. A-ll — Ampere-hour and Watt-hour Capacities. A-12 — Storage Battery Efficiency. A-13 — Curb Service Instruction Sheet. A-14 — Battery Diagnosis Prior to Opening. A-1S — The Cadmium Test on Charge and Discharge. A-16 — Testing Battery Jars. A-17 — How to Open a Lead Storage Battery. A-18 — Winter Storage. A-19- — Minor Defects and Repairs. A-20 — Lead Burning. A -21 — Major Defects and Repairs. A-22 — Installation of New and Old Batteries. A-23 — Care of a Storage Battery. A-24 — Testing and Repair Equipment. A-25 — Electric Vehicle Operation. A-26 — Charging Equipment. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers m \r ' * ' I Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair H _ Hf- H M SYMBOLS Single Battery Cell. Battery of Two Cells Connected in Multiple or Parallel. Battery of Three Cells Connected in Series. Ammeter. Voltmeter. Wattmeter. Single Pole Switch. Double Pole Switch. mrnw Resistance. { AAAA/WVW Variable or Adjustable Resistance. OR — i Lamp. Positive Terminal of Battery. Negative Terminal of Battery. Armature and Brushes of Motor or Generator. Wires Crossing. Wires Connected. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Digitized by the Internet Archive in 2017 with funding from University of IllinoisdWrb&na-Champaign Alternates ' https://archive.org/details/looseleafshopman00burl_0 Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair PREFACE The effort has been throughout this work to get away from a theoretical treatment of battery prob- lems and discuss the topics in a practical manner. The information given in many cases does not absolutely agree with any one make of battery, but is sufficiently accurate for commercial work. The author’s broad experience as superintendent, electro-chemist and consulting engineer for several of the largest battery companies in the United States, has been responsible for this brief and vet inclusive treatment of the subject. In handling the subject of “Battery Testing and Repair,” the methods of treatment used previ- ously have been greatly modified. The theoretical work requisite for a clear understanding of the test and other allied information is placed on the rear of the test sheet. The practical test and the explanatory material is thus closely correlated. This is almost impossible in the average treatment of shop or laboratory work. The “Loose Leaf” method makes it possible to use the assignments in any order the instructor may desire. The lead battery is only considered inasmuch as the average service station is not equipped to re- pair the Edison battery economically. GENERAL INSTRUCTIONS FOR SHOP WORK The greatest benefit to be derived from this course is the ability to investigate, determine and rectify the difficulty. All commercial batteries differ mostly in minor details. It is important to know these details in order to make quick repairs. Experience has proven that the best results can only be obtained through individual effort. Note (a) When assigned to a problem, go immediately to the station where the work is to be done. (b) Read carefully the directions given on the assignment sheet. Be sure you understand what the test calls for. (c) Get whatever meters, tools, wire, etc., are necessary from the stock room, and examine meters carefully to see that the instruments are in good condition. (d) All ammeters should be properly fused. (e) Obtain all information available on the test being conducted and incorporate the same in your “write up.” (f) Keep a record of the time required to perform each operation. This information will prove very valuable in estimating the cost of repairs. Instructor’s Note: The instructor is expected to supplement this course with lectures, demonstra- tions and discussions, on uses, characteristics, advantages, disadvantages, chemical reactions, etc., of Plante, Faure and Edison Batteries. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Laboratory Manual REPORT BLANK (2) Course Number: Name of Test: Date: ___ ’ Name of Student: Object of Test: Apparatus : References : Diagram of Connections or “Set-up”: i i i Reserve this space for In- structor’s Check on Connec- tions. Test Data: No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Sample Calculation: Calculated Data : No. 1 2 3 4 5 6 7 8 9 10 11 — 12 13 14 Theory and Detail of Test: Results and Conclusions: Reserve this space for final check of Instructor. Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair DEFINITIONS OF TERMS FREQUENTLY USED IN BATTERY WORK Acid: The solution used in the battery. See Electrolyte. Active Material: The peroxide on the positive plates and spongy lead on the negative plates. Alternating Current (a. c.) : Electric current which periodically changes in direction. Cannot be used in battery charging except with a rectifier. Ampere (amp.) : An electrical unit of measurement to measure the rate of flow of electricity. Ampere-hour (amp. hr.) : Product of amperes and hours, or the unit used to measure quantity of electricity. Battery (batt.) : Two or more cells connected and used together. (Also used commercially when referring to one cell.) Bridge: Supporting ribs in the jar to raise the plates above the bottom. Buckling: The warping of the positive plates. Burning: The process of welding two pieces of lead by melting them along the line of contact and permitting them to run together. Burning Bar: The bar of lead that is used to fill in the joint where two pieces of lead are burned together. Cadmium (cd.) : A metal in the shape of a pencil used to test condition of positive and negative plates by voltmeter readings between said cd., (when inserted in the electrolyte) and the regular plates. Capacity: The Ampere hour (amp. hr.) rating of a battery depending on the rate of discharge. Case: A container which holds cells of a battery. Cell: A complete battery unit, consisting of plates assembled in one jar with electrolyte and cover. Cell Connector: See connector. Charge: Passing direct current through a battery to replace the chemical energy used on discharge. Charging Rate: The proper ampere rate used to charge a battery. Connector: A means of electrically connecting cells together or to the external circuit. Corrosion: The action of the electrolyte upon connectors, terminals, battery hold-downs, or any metal with which it comes in contact. Cover: Cover to prevent slopping of electrolyte and foreign matter entering the cell. Cycle: One charge and discharge. Density: Gravity or specific gravity. Developing: Bringing a new or repaired battery up to its rated capacity by one or more cycles of charge and discharge. Diffusion: The movement of acid within the pores of a plate. Discharge: The flow of electric current from a battery in opposite direction to flow on charge. Dry: Applied to a storage battery with semi-solid electrolyte, or to a battery with insufficient electrolyte. Electrolyte: Correct name for conducting fluid inside any cell. Element: The assembly of a pos. group, neg. group and separators. Equalization: The movement of acid in the cell and in the pores of the plates tending to equalize the gravity throughout the cell. Equalizing: Bringing the electrolyte in all battery cells up to the same density. Evaporation: The loss of water from the electrolyte due to charging or heating. Finishing Rate: A rate approximately one-half the charging rate used when a battery is practi- cally charged, or when the charge is to continue longer than the prescribed time for the charging rate. Flooding: Filling the cells to overflowing with either acid or water. Forming: The electrochemical process of changing the “green” pasted and lead plates into active, positive, or negative plates. Foreign Substance: Injurious materials. Freshening Charge: A light charge given a battery after standing idle in order to bring it up to “full charge.” Gassing: The bubbling of hydrogen and oxygen gases which rise to the surface of the electrolyte when a battery is nearing “full charge.” Gravity: A popular term for specific gravity. Green Plates: Unformed plates. Grid: The metal frame-work which holds the active material. Group: Two or more plates of a kind assembled as a unit. Hold-Down: A means of holding separators in position and preventing them from floating. A means of holding a battery in position on the car. Hydrometer: An instrument for measuring the gravity of the electrolyte. Jar: A container of insulating material in which the elements are placed after assembly. Lug: The projection from a plate to which the connecting strap is burnt. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Mud: Sediment in the bottom of the jar. Ohm: An electrical unit of measurement used to measure the resistance of the circuit. Over-charge: Charging a battery until gas is given off at a low rate of current. Gas is generally an indication that the cells are fully charged when the rate of charge is low. Over-discharge: Discharging a cell below the critical point of voltage depending upon the rate of current flow. Paste: The mixture of lead compounds, etc., which upon forming become the active material. Plate: The properly formed pasted grid. Positives are reddish brown, and negatives slate gray. Polarity: The electrical position which one part of a circuit has to another. If the current is flow- ing to it from another part, it is said to have negative polarity and the other to have positive polarity. The positive plate has therefore a positive polarity. Positive: The terminal from which the current leaves the source of energy. Marked “Pos.” or l +”- Post: The terminal of a cell to which the external circuit or another cell is connected. Potential Difference : Voltage. Rate: The time or number of amperes for charge or discharge. Rib: (See Bridge). Ribbed: (See Separator). Reversal (of Voltage) : The condition which occurs when a battery is over-discharged or charged in the wrong direction. Sealing: The fastening or enclosing of the battery with a compound which will adhere to the cover, jar sides, and posts, and prevent leakage of electrolyte. Sediment: The accumulated particles of active material in the bottom of the cell. Also called “mud.” Sediment Space: The space between the “bridges” at the bottom of the jar. Separator: The spacer (wood, rubber, etc.) placed between plates of opposite polarity to permit acid circulation but prevent contact. Separators are generally “ribbed,” “grooved,” or “corrugated.” Short Circuit: (Internal) The connection of plates of opposite polarity due to broken separator, accumulation of sediment, or foreign metallic substance within the cell. (External) : The flow of electric current through an unknown or uncontrolled path. Specific Gravity: The density or weight of acid as compared with a like amount of water. Spray: The mist which arises when a battery is gassing freely. This mist consists of fine par- ticles of electrolyte. Starting Rate: The rate used when starting a charge. This rate may be in excess of the normal rate and is not injurious unless the temperature rises above 105° F., or heavy gassing is caused. Strap: The lead connector which binds all plates of like polarity into one group. Sulphate: A popular term for lead sulphate. Sulphated: The condition of a cell which is under-charged. This is due to insufficient charge or “self-discharge.” Sulphate Reading: The abnormal voltage reading when a sulphated battery is placed on charge. Terminal: The post to which outside wires are connected to the battery. Vent Cap: The cap for the filling tube constructed so as to permit the escape of g'asses and prevent the spilling of electrolyte: Vitriol: Term used for “Oil of Vitriol” or concentrated sulphuric acid. Volt: The unit of measurement used to measure electrical pressure. Washing: Removal of mud from the jars and rinsing of the plates. Watt: The unit used to measure electrical power. The wattage of a circuit is the product of the voltage and amperage. Watt-hour: The unit of electrical work. The product of watts and hours. Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers ljoose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-l— THE CONSTRUCTION OF A STORAGE BATTERY Object — To become familiar with the detailed construction of a starting and lighting battery of standard make. Apparatus — A six volt storage battery which has either been sectioned or a battery which is dry and suitable for disassembling. Method 1 — Examine the exterior, carefully noting the information given on the name plate and other de- tails which may be peculiar to the size and make of battery. 2 — Open the battery with the utmost care so as to note all the details of construction and be able to reassemble the battery properly. The following sketch represents the average battery. Name the parts and state wherein the sketch differs from the battery examined. Answer the following from your observation: 1 — What is the color of the plates connected to the -f- terminal? 2 — What is the color of the plates connected to the — terminal? 3 — How many -f- plates are there in each group? 4 — How many — plates are there in each group? 5 — Why is there one more negative plate than positive? 6 — What are the separators for? 7 — Which side of the separator faces the pos. plate? Why? 8 — Of what are the separators made? 9 — How are the separators held in place? 10 — What is the space in the bottom of the jar for? 11 — Name fifteen uses for storage batteries. 12 — How many covers has the battery? Why? 13 — How is the battery sealed to prevent “slopping?” 14 — Of what material is the jar composed? 15 — Why is the vent cap constructed as it is? 16 — Why cannot a cork be used? 17 — What metal is used for the connectors? Why? 18 — Of what material is the case composed? 19 — Is it protected in any way? How? 20 — Of what material are the plates (grids) made? Why? Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Theory — The term storage battery is misleading inasmuch as no electrical energy is actually stored up in a battery. A battery is a store house of chemical energy which, upon demand can be changed into electrical energy. In other words a battery is a device used to change chemical into electrical energy, and a storage battery is a (reversible) device in which electrical energy can be changed to chemical and chemical back again into electrical. The terminals of a battery are labeled + and — indicating the “poles” of the cell from which electric energy passes to the external circuit and returns. The chemical action which takes place with a flow of current is not hard to understand and will be discussed later, but the cause of the existence of electrical energy cannot be explained here any further than to say that between every conductor and the medium surrounding it there is an electrical pres- sure. This electrical pressure causes a flow of electrical energy when a conducting medium is present. With the flow of electrical energy there is a consumption of material inside the cell. This consump- tion is concentrated largely at the plate connected to the negative terminal. Hence this plate is gener- ally called the “positive” or “fuel producing” electrode. In the lead storage battery this plate or elec- trode is composed of “spongy” lead and it is from this plate that the electrical energy starts on its cycle through the cell to the “peroxide” electrode, and thence to the external circuit. With the passage of electric current through a solution decomposition takes place. This principle is made use of in restoring (recharging) a cell to its former condition after it has expended its chemical energy in forcing electric current through the external circuit when on discharge. Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-2— THE CONVERSION OF CHEMICAL INTO ELECTRICAL ENERGY. Object — To become familiar with the principle of all batteries, more especially primary cells. Apparatus — Small pieces of sheet copper, aluminum, lead, iron, carbon, zinc, lead, a piece of old pos. storage battery plate, or any other metals available. A low reading voltmeter, weak sulphuric acid, and a glass battery jar. Method — Place the strips of metal or elements in the jar of acid, two at a time, and connect to the voltmeter, record the deflection or throw of the needle. (Be sure the metals are cleaned before use). Record the groups of combinations in the order of deflections. It will be noticed that the sub- stances giving the greatest throw of the needle are the substances which are used commercially for battery purposes. Record the elements in the order of their activity as indicated by meter deflections. Questions 1 — Did the position of the needle of the voltmeter remain constant when the circuit was kept closed? Why? (Observe especially when copper and zinc are the elements). 2 — What is a positive element? 3 — What is a positive terminal? A — From your observations which group would you select if your were constructing a primary cell? Why? 5 — Test this group again permitting the circuit to remain closed for ten minutes. Does the needle deflection remain constant? 6 — Clean the elements used above (5) and test again. Is the throw of meter needle the same as in (5) ? Why? There is evidently a condition at the surface of at least one of the elements which, if re- moved, would increase the cell’s activity. 7 — Did the separation of the elements influence the meter reading? Why? 8 — What deflection was noticed when the elements were in contact within the solution? 9 — If you were constructing a battery would you want a wide separation between plates? Why? Theory — It is evident from the results of the test that some metals are extremely active in a solu- tion of sulphuric acid. Chemical action should be suppressed as much as possible, and for this reason the zinc element, which is one of the most active, is generally amalgamated. (Amalgamation is done by rubbing mercury onto the surface of the zinc. The mercury will unite with and protect the ex- posed metal). If other solutions, as sal ammoniac, were used it would be noticed that the action is much weaker. It is, however, interesting to note that the size of plate in solution, or the distance the plates are apart, have no noticeable effect upon the deflection. It is evident, therefore, that the voltage or force which causes the current to flow is not dependent upon size, shape, or distance between the plates, but upon nature of the elements and the solution. The effect of the electric current upon the elements when a cell is discharging is to use up one or both. There is also a change in the electrolyte showing that there is a chemical reaction taking place with the flow of electric current. A primary cell may be defined as a cell in which the elements must be replaced after the cell has been depleted by use. In other words, it is an apparatus used to change chemical into electrical energy. Due to the fact that the voltage, and hence the current do not remain constant in service, batteries of the types tested are only used for open circuit work. Several modifications have been made to overcome the inherent defects of this type of cell by eliminating the cause of voltage drop namely : polarization. Further tests will be made on polarization later. Copyright 1922, B. B. Burling Bruce. Milwaukee. Publishers ( BK , ... Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-3— THE HYDROMETER AND THERMOMETER Object To understand the principle of and uses of the hydrometer and the influence which tem- perature has upon its reading. Apparatus — A commercial battery hydrometer, a floating thermometer reading from zero to about 120°, some battery acid, an earthen container, and a heating unit. Method 1 if the hydrometer being tested has a Baume and a Specific Gravity scale, examine and de- termine Baume readings and equivalent gravity readings. Plot a curve showing the relationship between the two systems of testing acid strength. 2 If the weather is cold, place some acid outside to cool and take readings of gravity and tempera- ture (F.) through a range of at least fifteen degrees. If ice is available the test can be performed indoors. In case it is inconvenient to cool the acid arrange some means of heating enough acid for testing and take readings of gravity and temperature (F.) through a range of about 30° F. From this data cal- culate the increase or decrease in gravity for each three degrees change in temperature. Average the results obtained. Questions 1 — What degree Baume is equivalent to 1.300 sp. gr? Fig. 5. 2 — What effect does a change in temperature have upon Baume readings? Figs. 5, 6. 3 What is the gravity reading at zero degrees F. of acid testing 1.280 at 70° F.? Commercial Types Fig. 5. JD?$rt>es Cor re chon For 1*0 1 20 l 10 S5 — _£ |00 — ^ =1 90 El — £ 80 £ 70 60 = ^ ■*3 C 50 *>. c£ — 5 Ae 30 -1 — a; — 1 20 _«b — fi 10 — 3 <0 Fig. 6. Theory — The specific gravity of a solution is the weight of a given volume compared with a like volume of water. The specific gravity of water is 1.00. If pure acid has a gravity of 1.83 it is 1.83 times heavier than water. There is an expansion or contraction of most substances when subjected to a change in tempera- ture. This change in volume without change in weight simply means that the weight of a definite volume fluctuates with changes of temperature. The buoyant effect is always equal to the weight of the liquid displaced so a hydrometer can be graduated to measure the weight of the solution displaced and as this weight changes, due to fluctuat- ing temperatures, the reading on the hydrometer will show a corresponding change. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers * * ; * • «i ■' Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-4— THE ELECTROLYTE Object — To determine the properties of battery acid. Methods of handling. Mixing. Propor- tions acid and water, etc. Apparatus — An earthen container. A means for measuring acid and water, concentrated acid, dis- tilled water, hydrometer, thermometer and storage battery being charged. Method 1 — Measure out carefully five (5) portions of pure water, and then carefully (while stirring) pour into the water two (2) portions of acid. Test with the hydrometer and thermometer and calculate the gravity at 70° F. 2 — Measure the electrolyte and explain the cause for any noticeable discrepancy. 3 — You will probably not be able to measure the expansion or contraction of the solution due to temperature changes, but calculate the per cent expansion for a change of forty (40) degrees F. 4 — Is this sufficient to cause a normal battery to overflow when on charge ? 5 — Explain the reasons for a “slopping” battery. 6 — Test each cell of the battery carefully with hydrometer and thermometer and explain, if possible, the cause of any variation in acid readings. Questions 1 — What proportions of acid and water are there in commercial battery acid? 2 — Are these proportions by weight or volume? 3 — What kind of container should be used for acid? Why? 4 — Describe the method of “mixing acid.” 5 — Does acid evaporate? 6 — How often would you “water the battery?” Why? 7— Explain why two portions of acid and five portions of water do not make seven portions of electrolyte. 8 — When should acid be added to a battery? 9 — Explain why the middle cell should be watched. 10 — What kinds of water should be used in a battery? 11 — When should water be added to a battery in winter? Why? 12 — What dangers and difficulties are involved in a “slopping” battery? 13 — How high above the plates should the electrolyte be in a battery? How low? 14 — Why not fill the battery full when adding water? 15 — Why should spilled acid or water around a battery be immediately neutralized and wiped off? 16 — What is meant by HsSO»? 17 — Where there is a large quantity of acid (electrolyte) in a battery why is the density generally lower than where there is a limited quantity? 18 — Is a metal container suitable for water storage? Why? Theory — The electrolyte of the commercial lead cell is sulphuric acid (H s SO«) composed of hydro- gen, sulphur and oxygen in chemical union plus sufficient pure water to reduce it to the desired density. Pure acid has a specific gravity of 1.835. This acid is so strong that it will char wood, cause water to boil and burn the skin. The affinity which concentrated acid has for water is largely the cause of the above and other properties. It is difficult to realize the care which must be exer- cised in maintaining a pure electrolyte. Electrochemical action is always present and the addi- tion of impurities in the water or the acid will in time cause a disintegration of the positive plates and a local action discharge of the negative. “A little won’t hurt,” you are likely to say, but with the realization that every week or two throughout the year water is added to the cells it becomes evident that impurities are liable to accumulate in dangerous proportions. The properties of strong acid naturally lead to the assumption that these properties exist in the ordinary electrolyte. This is to some extent the case although less in degree. The wood separators are liable to decompose under the action of acid and temperature. Keep the acid below 1.300 and 105° F. During the normal use of a battery water only is evaporated and hence water should only be used to replace the loss. The addition of electrolyte, to take care of this evaporation, would mean a high gravity on full charge and a resultant shortening of the battery’s life. Never add acid until you are certain the low gravity is due to sloppage or leakage. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair In order to determine the condition of a battery individual cell readings should be taken, although weekly readings of the middle cell are recommended as this cell generally gives trouble first. When plates are immersed in electrolyte a gradual change takes place and the sulphate (SO«) of the acid unites with the active material of the plates. This is called “sulphation.” Periodic charges at least once a month are necessary to keep any battery in good condition. During the process of sulphation (battery discharge), whether through use or through idleness, the acid becomes weaker until the battery will act sluggishly, or even fail to turn “ the engine over.” Such weak acid freezes easily. The electrolyte of a battery in a charged condition (1.300) cannot freeze. In cold weather a battery should be maintained in a charged condition. Any cell which shows a “low gravity” (weak acid) should be examined carefully to determine and relieve the cause before freezing, breakage, or other damage is done. Chemicals like ammonia and soda neutralize acid. Always keep some on hand. Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair V job A-5— THE VOLTMETER Object To study several types of D. C. voltmeters, check their accuracy and connections. Apparatus — A pocket type of voltmeter. A permanent magnet meter (preferably a Weston), a source of electrical energy of sufficient voltage to test each scale of the meters, and suitable resistances. Method I. Examine each meter very carefully, recording the following points : (a) The type of meter, number, and name of manufacturer. (b) The range of scale or scales. (c) The construction: permanent parts, movable parts, bearings, zero correction and damping. (d) Internal wiring diagram and connections. (e) Test parts with a compass. State results. II. Show by diagram the method used in placing a voltmeter in a circuit to test the voltage of a battery and the voltage across an incandescent lamp. Fig. 7. III. Arrange suitable resistances or lamps as shown in the diagram and connect the pocket and standard meters as indicated. Shift the connections as shown and take simultaneous readings of both meters. Plot the data obtained with the standard meter readings on the horizontal, and the pocket meter readings on the vertical. For very accurate testing all meters should be thus calibrated at fre- quent intervals and the “calibration curve” used to correct subsequent readings. Questions 1. What would take place if the direction of current were reversed through the meter? 2. Is this true with every meter? 3. If the magnet were accidentally reversed what would be the result? 4. Would temperature affect the readings of the meters tested? Why? 5. What would be the result if the meter were connected in line with the current? Connect thus and explain. 6. What method could be devised to use a low reading voltmeter on a higher voltage line than the range of the meter would indicate? 7. Is this method used in a two or more range meter? 8. Would it be possible to use the meters tested on alternating current? Why? Theory — Direct current voltmeters in general use are of three types : solenoidol, permanent magnet and electrodynamometer, although for special purposes hot wire or electrostatic meters may be used. Probably the oldest style of meter is the solenoidol or movable core type. The fundamental principle involved in most of the commercial meters is magnetic attraction and repulsion. In the solenoidol type a core to which is attached an indicator, or pointer is magnetically attracted into the solenoid. The extent of movement is naturally proportioned to the attraction, and the attraction is in turn proportional to the current flowing through the coils. The amount of current flowing through the coil or coils is proportioned to the electrical pressure (voltage) back of the current, hence the movement of the core or plunger is proportional to the voltage. The best volt- meters have a very high resistance and their current is practically negligible. Cheap pocket, portable or wall instruments are seldom very reliable. In meters of fixed polarity it naturally follows that there must be a certain direction of current in order to produce a definite second polarity and cause a cor- rect indication. This principle is also noticed when a magnet is brought near a compass. One pole attracts and the other repels. In meters the polarities may be produced by a permanent magnet and a solenoidol magnet, or by two solenoidol magnet coils. The Weston D. C. meter is typical of the permanent magnet and solenoidol magnet coil. All meter movements must be “damped” so as to avoid oscillation of the needle. This may be done by mechanical or electrical means. Air, oil and other liquids have been used with success. Natur- ally air would be best suited for portable and oil for wall or stationary meters. The electrical method of damping is by the formation of “eddy” currents in the movable parts of the meter. These electric cur- rents are caused when any conducting material is moved in a magnetic field, as would be the case when the movable part of the meter oscillates in the permanent or electromagnetic field. The effect of the eddy currents is to oppose the motion which crea J ed them. This is what prevents any appreciable oscillation of the needle in the best types of porta' le meters. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers •' . 1 . 1 V * • • Loose Leaf Shop Manna] Burling Vocational Series Battery Testing and Repair Job A-6— THE AMMETER Object — To study several types of D. C. ammeters check their accuracy and connections. Apparatus— A pocket type of ammeter, one or more portable meters of standard make, source of electrical energy (six volt storage battery) and suitable regulating resistance. Method I. Examine each meter carefully recording the following information : (a) Type of meter, maker’s name and meter number. (b) The range. (c) The construction, permanent parts, movable parts, bearings, zero correction and damping. (d) Internal wiring diagram and connections. (e) Test parts with compass. State results. II. Show by diagram the method of connecting an ammeter in a circuit. III. Arrange a variable resistance in series with the various meters being tested and connected to a six volt source of energy. Adjust the resistaice so that simultaneous readings can be taken of all meters at different points on the scale. Plot the data for the standard or most accurate meter on the horizontal and the other data on the vertical. Questions 1. What effect would a reversal of current through the ammeters tested have? Why? 2. How is the range of a meter changed? 3. Explain how you would measure a thirty ampere current with a five ampere range meter. What properties should the metal to be used for the shunt have? 4. Dry cells are generally tested with an ammeter. Why would it be disastrous to attempt to test a storage battery in the same way? 5. Can the meters be used on A. C.? Why? Theory — The D. C. Ammeters are of the same types as explained under voltmeters and the theory of operation is the same. In the construction of an ammeter the resistance is negligible or very low, while in the voltmeter the resistance is high. This explains why a voltmeter can be connected directly across a line while an ammeter would burn out if so treated. Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-7— POLARIZATION OF PRIMARY CELLS Object — To study the characteristics of commercial primary cells. Apparatus — A dry cell, Edison primary cell, gravity cell, ammeter, voltmeter and suitable re- sistance. Method Short circuit each of the cells through a resistance, reading the amperage and voltage every min- ute for ten minutes. (At each minute interval open the circuit for an instant and record the voltage.) Record the voltage when cells are on open circuit and also the instant the switch is closed for the dis- charge. After the discharge of ten minutes open the circuit and immediately read the voltage. (Con- tinue to take voltage readings every half minute until the readings cease to change.) Plot the data obtained from each of the three cells and in the write-up compare, 1st — Voltage discharge curves. 2nd — Voltage polarization curves. 3rd — Voltage recuperation curves. Questions 1. Which of the cells tested would be most suitable for open circuit work? Why? 2. Which would be most suitable for closed circuit work? Why? 3. State various commercial uses for open and closed circuit batteries. 4. Explain the construction of each cell tested including the elements used, the electrolyte, depolarizer, etc. 5. Explain the action which takes place in each type of cell when on discharge. 6. Is it possible to charge a dry cell by the passage of an electric current? Why? 7. What common test is used to determine the condition of dry cells? 8. Is this an entirely satisfactory method of testing? Why? 9. Can the same method be used in testing storage batteries? Why? Theory — The fact, known to all electro-platers and electro-chemists, that metals including hydro- gen, pass through a solution in the direction of the current, gives us an explanation for polarization. When an electric current flows through a water solution decomposition takes place, and hydrogen, travelling with the current, is deposited on the “positive plate.” If the hydrogen is not taken care of by chemical, electro-chemical or mechanical means it will set up a voltage in opposite direction to the flow of current. This is the situation which exists in what is known as a polarized cell. In all com- mercial primary cells so called “oxydizing agents” are used because hydrogen and oxygen have a great affinity for each other. The union of two parts of hydrogen to one of oxygen forms water and is expressed chemically as HaO. The oxygen may be supplied in the plate as a part of the element, or in the medium surrounding it. Both methods are used commercially. In the Edison primary cell the oxygen in the copper oxide plate is used up in overcoming polarization. In the dry cell the manganese dioxide surrounding the carbon element is used for the same purpose. When ignition for motor vehicles was performed with dry cells, it was necessary to develop an open circuit system so as to prolong the useful rife of the cells and give opportunity for the depolar- izer to do its effective work. The well known Atwater-Kent system proved one of the most efficient. Other systems of the closed circuit type proved too much of a drain upon the cells and made it ab- solutely necessary to use a non-polarizable, or a storage battery. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers H8E Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-8— SERIES AND PARALLEL COMBINATION OF CELLS Object — To study the effect of various combinations of cells upon ammeter and voltmeter readings. Apparatus — D. C. Ammeter, D. C. Voltmeter, flash light battery, three No. 6 dry cells, and a three volt flash light bulb, (storage cells are not used in this test because of accidental wrong connections.) with an ammeter and a dry cell. Method I. (a) Measure the voltage of the flash light battery cell and the voltage of a No. 6 dry cell. Explain. (b) Connect two dry cells in series, measure the voltage of the combination. (c) Connect three dry cells in series, measure the voltage of the combination. (d) Connect a flash light cell and three dry cells in series, measure the voltage of the com- bination. (e) Reverse one of the cells, and test voltage of the combination. Explain. (f) Make a commercial “flash test” of the dry cells individually. (g) Make a flash test of two dry cells connected in series. Be sure that these two cells have practically the same individual flash tests. (h) Connect these two cells in parallel. Test voltage and flash. II. (a) Connect the flash light bulb in series with an ammeter and a dry cell. Test voltage across cell when delivering current. (b) Connect in series with two dry cells. Note reading. Test voltage across each cell when current is flowing. (c) Connect three cells in series and test likewise. How do the readings of the ammeter and voltmeter differ when the lamp is connected in the circuit? Explain. (d) Connect two dry cells in parallel with the lamp. Note readings of current, and test voltage across each cell. (e) Connect three dry cells in parallel with the lamp. Note current reading and test voltage across each cell. (f) What effect does the addition of cells in parallel have upon the current through an external resistance circuit? How does this differ from the data obtained when cells were connected in series with practically no external resistance as in the flash text? • (g) How does the cell voltage change when delivering current? Theory — From the discussion given under Job No. 2, it will be remembered that different metals immersed in an electrolyte gave correspondingly different voltages. It was probably also noted that the surface exposed to the electrolyte had no appreciable effect upon the voltmeter readings. In primary batteries, such as the drycell, the internal resistance is quite high although not as high as in the gravity or wet cell. In short circuit (flash) tests this internal resistance limits the flow of current. A storage cell with the plates close together, an electrolyte of very good conductivity and a large plate area has a very low internal resistance. This accounts for the fact that high amperages of several thousand can be obtained on a dead short. (Never short circuit a storage battery). The plates of the ordinary storage cell are connected in parallel and thus increase the current out- put without changing the voltage. Other things being equal a battery (cell) of more plates will deliver considerable more current than one of fewer plates. When storage batteries were only used for lighting and ignition, large amperage output with large plate area was unnecessary, but with a cur- rent demand of from 100 to 200 amperes every time the engine is started, it is necessary to have a bat- tery of greater plate area. The cells of a battery are connected in series to give six or twelve volts as desired. The com- mercial starting and lighting battery is a parallel series combination of plates. In parallel to give high amperage and in series to give voltage. The terminal voltage (voltage when on discharge) is a changing quantity depending upon the rate and duration of discharge. The difference between the open circuit voltage and terminal voltage is the pressure lost in forcing the current through the cell or battery. The lower the internal resistance, the higher the terminal voltage, and the more “pep” the battery has. The high internal resistance of the “Edison” storage cell makes it less suitable for starting pur- poses. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-9— CHARGING BATTERY USING HYDROMETER FOR TESTING. Object — To become familiar with the use of a hydrometer in testing the state of charge of a battery. Apparatus — A storage cell, or preferably a six volt battery, hydrometer, thermometer, source of D. C. energy for charging, an ammeter and a regulating resistance. Method 1. Examine battery and determine charging rate from name plate. (See theory). 2. Determine by test whether the supply of energy is direct or alternating. 3. Be sure the plates of each cell are properly covered with electrolyte. If not supply distilled water up to the proper height (about above top of plates). 4. Start the battery charging at the normal or ten hour rate, and test the gravity of each cell at hourly intervals until three successive readings show no change. 5. Test the temperature, make correction of gravity readings for 70° F. and equalize the acid if necessary. 6. Continue charge for one hour to insure proper mixing of acid and water. Test again and re- peat equalization and further charge if necessary. Questions 1. What different methods can be used to determine whether the energy available is D. C. or A. C. ? 2. Why is not A. C. used to charge a battery? 3. Explain completely how you would charge a battery, maximum temperature permissible, charging rate, gravity, and direction of current through battery? 4. When did gassing begin? Is this any indication of condition of charge? 5. Was there any noticeable change in the color of the plates during charge? What? In case the gravity fails to rise or show a change after an hour’s charge the battery should be sent to the repair room. Where many batteries are being charged hourly readings on all should be made. In order to know how the cells are “coming up” distinctive chalk marks can be placed on each battery when making the round. The following markings have proven very satisfactory. Distinctive Marks Gravity Readings —5 1.255 — 4 1.260 —3 1.265 —2 1.270 — 1 1.275 — or 0 1.280 + 1 1.285 +2 1.290 +3 1.295 +4 1.300 Theory — The term ampere hour is used frequently in connection with storage battery work and is equal to the product of the flow of the current in amperes and the time the flow is maintained. Thus, a discharge of ten (10) amperes for 10 hours indicates that the battery has a capacity of at least 100 ampere hrs. at the 10 hr. rate. Temperature and Charging Rate — In determining the rate of charge for the average battery, it is customary to take 1/10 of the amp. hr. capacity, or if this is not available, one (1) ampere for each pos. plate in a cell. Where batteries of different capacities are connected in series the rate for the smallest battery should be used. In case the temperature should rise about 100° F., frequent observation should be made. If the temperature rises above 105° F., disconnect until the thermometer shows less than 90° F. A sul- phated battery generally heats up on charge. Many times this is the first indication that the battery Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair is in a dangerous condition. After all cells are gassing freely at the 10 hr. rate, but the acid is still low, reduce to y 2 the 10 hr. rate, and continue until fully charged. Sulphated Battery — In case the battery is sulphated badly, and the temperature again rises to about 100° F., reduce the charging rate to 1/20 of the ampere hour capacity, and continue until all indications point to a complete charge. If the battery still is sulphated discharge down to 1.8 volts and charge again. Beware of patented preparations to reduce the sulphate. Explosive Gas — During charge never “spark” a battery, as is so often done by inexperienced men, by snapping a short circuiting wire across the terminals to see if the battery has “lots of pep.” The gasses inside the cell are explosive and disastrous results are likely to follow such methods of testing. For this same reason never bring an exposed flame near the vent. In case a flame is needed for repairs on the battery remove from charging line and blow into the vent holes to remove the gasses before proceeding. Conditions at Full Charge — In determining whether a battery is fully charged, (1) All cells should be gassing uniformly at the low rate, (2) The gravity of all cells should remain constant for a period of at least two hours, (3) In the fall of the year the acid strength should be equalized to 1.280-1.300, (4) The voltage of all cells should be equal and over 2.5 while on charge. Different makes of batteries have different back voltage on charge. This and the back pressure, due to sulphation, makes the voltage by itself very unreliable. Copyright 1922. B. B. Burling Bruce. Milwaukee. Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-10— COMPLETE TEST OF SIX-VOLT STORAGE BATTERY (VOLTMETER AND HYDROMETER) Object — To make a discharge and charge test on a storage battery. Apparatus — Lead storage battery previously charged, ammeter, voltmeter, hydrometer, adjustable resistance and source of D. C. power. Method 1. Wire up the battery, ammeter, voltmeter and resistance for the discharge test and take open circuit voltage and hydrometer readings on each cell. 2. Discharge the battery at either the 1 or 3 hour rate until the voltage has dropped to 1.7 in the lowest cell. During this discharge take readings of terminal voltage and hydrometer at intervals of five or ten minutes depending on the rate. 3. When the terminal voltage of 1.7 is reached quickly reconnect for the charge at the same rate. Take readings at the same intervals as in discharge. Continue the charge until the gravity ceases to change. Be careful of temperature. 4. Plot the curves of voltage vs. time and specific gravity vs. time for the discharge and charge. (Use time on horizontal). 5. Tabulate all observations carefully. 6. Mark on the curves the point at which “gassing” appeared. Questions 1. How is the state of discharge determined? 2. How is the state of charge determined? 3. What is the highest and lowest voltage reading on discharge? 4. What is the highest and lowest voltage reading on charge? 5. What is the highest and lowest gravity reading on discharge? 6. What is the highest and lowest gravity reading on charge? 7. What is the gravity at discharge? 8. What charging voltage must be used for a six volt battery? 9. How many six volt batteries can be charged in series on 110 volts? 10. Explain what should be done if gravity is low? 11. Explain what should be done if gravity is high? 12. What would cause gravity to be too low? 13. What would cause gravity to be too high? 14. What four things influence the voltage of a battery in service? 15. How long will it take to charge a 120 a. h. battery at the ten ampere rate 16. What will be the cost of charging a six volt 120 a. h. battery at ten cents per kilo-watt hour? (a) If the 110 volt charging circuit is loaded to capacity? (b) If only one six volt 120 a. h. battery was on the circuit? 17. If no meters or testing apparatus are available explain method of charge. Theory — In determing the rate of charge or discharge, other than the eight or ten hour rate, the following rule will be found commercially accurate. Rule: In doubling the rate in amperes the time will be reduced to 1/3. Example : Rate in Amp. 10 2x10 or 20 2 x 20 or 40 2 x 40 or 80 2 x 80 or 160 Discharge in Hrs. 10 1/3 of 10 or 3 1/3 1/3 of 3 1/3 or 1 + 1/3 of 1 or 20 min. 1/3 of 20 min. or 7 min. It is not always possible to test a battery at its normal eight or ten hour rates. From the name plate information other rates may be calculated and the length of discharge approximated. Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair It takes time for acid to diffuse into the pores of the plates and aid in maintaining pressure and the resultant current flow. At high rates of discharge this lack of diffusion causes the loss in capacity noticed above. This also explains how a battery may deliver 100-200 amperes to turn an engine over and be “dead” in a few minutes, yet after a few moments’ rest will appear to have regained most of its original vigor. In testing any battery calculate the rate which will leave ample time for recharging. Never permit a battery to remain long in a discharged condition. Sulphation will result. Sulphation chokes the cell making it practically useless until it can be restored to its normal state. The end voltage permissible at the 1 and 3 hour rates is 1.7 volts, while at lower rates of dis- charge 1.8 volts is standard. At higher rates even lower end voltages are used. These rates, however, are not generally used in testing the portable type of battery. During discharge the acid gets weaker because of the uniting of the sulphate in the electrolyte with the active material in the plates. This sulphation is not dangerous if not permitted to continue some time before recharging. During the charging process the sulphate in the plates is transposed back to the solution. It is only when all the sulphate has been transferred that the gravity ceases to rise. The following formula is the chemical method of expressing this transfer of sulphate from the solution to the plates during discharge and the transfer back during charge. PbO* + 2H.SO. + Pb = PbSO« + 2PLO + PbSO< Discharge c Charge Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers L,oose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-ll— AMPERE-HOUR AND WATT-HOUR CAPACITIES AT DIFFERENT RATES Object — To become familiar with the behavior of a battery at different rates of discharge and charge. Apparatus — Six volt storage battery, heavy cable and regulating rheostat, voltmeter, hydrometer and ammeter of 200 amp. range. * Method 1. From the name plate calculate the different rates as indicated in Job A-10, and if possible run discharge and charge tests at the 8, 3, 1, and 1/3 hour rates. 2. From the data obtained compute the amp. hr. capacities and plot a. h. capacity vs. rate. 3. If the voltage readings are at equal intervals average the readings to get average voltage of charge or discharge. Multiply this voltage by the current rate of discharge and by the time to get the watt-hr. capacity. Watt hour = average voltage X current X time in hours. Plot the watt-hr. capacity vs. rate of dis- charge. In case the voltage readings are infrequent or irregular, plot the voltage-time curve and from this curve determine the average reading. Questions 1. Calculate the relationship which exists between amp. hr. capacity and rate of discharge. 2. Calculate the relationship which exists between the rate of discharge and the time. 3. Calculate the relationship which exists between the watt-hour capacity and rate of discharge. 4. From the curves drawn calculate the ampere hour capacity at the five amp. rate. 5. Calculate the ampere hour capacity at the 20 min. rate. 6. Calculate the ampere hour input at the 8, 3, 1, 1/3 hr. rates. Figure the end of charge at the point where the gravity ceases to rise. 7. Why is the ampere hour capacity not changed by adding cells in series but is increased when cells are connected in parallel? 8. How will the area of a plate affect its available capacity? Why? 9. How will the thickness of a plate affect its available capacity? Why? 10. How will the temperature of a battery affect its available capacity? Why? 11. Why will the rate of discharge affect the capacity? 12. What effect has service on ampere hour capacity? Why? 13. How will the watt-hour capacity be changed by adding cells in series? Why? Theory — From the tests it is evident that the ampere hour capacity of a battery means nothing unless the rate is also specified. The Society of Automotive Engineers has specified two tests which are considered standard for starting and lighting batteries. For lighting purpose the ampere hour capacity is figured at the five ampere rate down to a voltage of 1.8. For starting purposes the capacity is figured at the rate which will discharge the battery in 20 minutes down to approximately 1.65 volts. It is somewhat unfortunate that commercially the watt-hour capacity is not the determining or selling basis. It is evident that an Edison battery might have ample capacity in amp. hrs. and still be very undesirable for starting purposes. Various makes of standard storage batteries will differ widely on the watt-hour capacity and still be alike on the ampere-hour basis. The nature of the electrolyte, whether liquid or solid, high or low gravity, effects the wattage output. In fact any features of a cell which raise the resistance will decrease the terminal voltage and the resultant watt-hour capacity. The ampere hour capacity of a battery is dependent upon : 1st. The weight of active material in the plates. 2nd. The plate area. 3rd. The thickness of the plates. 4th. Temperature. 5th. Specific gravity of electrolyte. 6th. Previous conditions of service. 7th. Rate of discharge. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers nt Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-12— STORAGE BATTERY EFFICIENCY Object — To become familiar with the efficiency of standard makes of lead storage batteries, and also the ampere hour and watt hour capacity per pound of cell. Apparatus — Six volt storage battery different from the one used in Job A-ll, voltmeter, ammeter 200 range, hydrometer and regulating resistance. Method 1. Obtain the discharge and charge data at the five ampere and the 20 minute 2. Calculate the ampere hour input and output from the data obtained. 3. Calculate the watt hour input and output from the data obtained. 4. Calculate the ampere hour efficiency (output H- input = eff.), and the watt the two standard rates. Ampere hour output on discharge = Ampere hour efficiency. Ampere hour input on charge Watt hour output on discharge = Watt hour efficiency. Watt hour input on charge 5. Compare these efficiencies with the efficiencies obtained from data in Job A-ll. 6. Weigh both batteries and calculate the watt hour and amp. hour capacity per pound of battery weight. Questions 1. Is the heavier battery the safest to buy? Why? 2. Where would you look for a decrease in weight without loss in length of service? 3. Is the battery with highest watt hour or ampere hour efficiency always the safest to buy? Why? 4. What points would govern your selection of a battery for personal use? For selling? 5. Does 1.300 acid always indicate complete charge? Why? 6. Does two volt per cell of an idle battery indicate complete charge? Why? 7. Can you expect the same mileage from an electric vehicle in winter as in summer? Why? 8. Is 2.55 volts an indication of complete charge? Why? 9. What rule would you suggest in determining the state of charge of a battery? Theory — There are two distinct types of batteries in general use although both are not adaptable for starting and lighting. I. The lead battery whose plates are made up either of pasted grid or solid lead has a voltage of approximately two per cell and is capable of extremely high discharge rates. II. The Nickel-Iron cell whose plates are composed of nickled iron grid or holder with nickel oxide and flake nickel as the active elements has a voltage of about 1.25, but the high interval resistance pre- vents high discharge rates. Both types have their distinctive advantages for particular classes of service. Of the lead type, which is the most common, there are two divisions. The Plante or solid formed lead plate has the advantages which makes it serviceable for a stationary battery where life, weight and space are not sacrificed for portability. The Faure or pasted class of battery plate is extremely efficient from the standpoint of capacity per pound of cell, although life, weight and space are sacri- ficed in order to produce a battery suitable for the service desired in automobile work. rates. hour efficiency at Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers r* ^ ••• SflLLHKW Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A- 13 — CURB SERVICE INSTRUCTION SHEET Object — To determine object of “curb service” and the assistance to be rendered the car owner. Apparatus — (Equipment for curb service). Voltmeter 0-3-15 range, high rate discharge tester, distilled water, hydrometer, grease or vaseline, soda solution, several used batteries. Method 1. Test gravity of acid of a used battery. Make recommendations (to owner) as to freezing, temperature of battery, when to come for acid equalization. 2. Fill with distilled water. Make recommendations (to owner) as to filling, frequency of serv- ice, height of electrolyte, when to fill in cold weather. 3. If battery is reported as giving trouble and gravity tests O. K., or if electrolyte is so low that no test can be made, test each cell with “high rate” tester and voltmeter. Make recommenda- tions (to owner) as to apparent repairs necessary. 4. Should repairs be necessary detain owner while a “loaner” is installed. Helper opens cell for immediate inspection. Cost of repair is given. State time required for repair. 5. Should repairs be uncertain, make recommendations about the bench charge, test, etc. Install “loaner.” 6. If battery is O. K. brush off dust, brush with soda solution to neutralize any acid on top of cells and corrosion at terminals. Wipe dry and cover terminals with grease or vaseline. Make recom- mendations as to proper care to avoid like conditions in the future. Note: Report in detail the recommendations which would be made to owner in each of the above tests. Questions 1. What trouble may result from corroded terminals? 2. How would you determine whether the terminals are corroded? 3. Which terminal seems to be corroded the more? 4. What is liable to result if the battery is not secured in position? 5. If the lighting and ignition seems O. K., but the motor cannot turn the engine over, what trouble may be located in the battery? 6. If lights will not burn, what trouble may be located in the battery? 7. What care should be used with tools around a battery? Why? 8. How should water be added to a battery? Explain in detail. 9. What will result if soda solution gets inside of cells? 10. Why is periodic inspection advocated by all manufacturers? 1 11. If battery is low why is it generally advisable to remove battery from car to recharge it? Theory — The object of “curb service” is to keep in close touch with battery owners. Real service along the lines suggested will bring reward. Customers will be held and new ones obtained. Curb service is the connecting link between the firm and the future and past customer. Curb service is generally used to mean “watering a battery” but occasionally acid is added. This is a dangerous practice. Wherever possible get the battery in the shop for 24 hours charge and equalization. Be careful not to transfer acid from one cell to another when testing gravity. It is always advisable to record the gravity readings in a manner that will indicate the general condition of each cell when the customer again calls for service. It is unnecessary to keep this record at the service station, but it should be recorded on the battery box, floor board of car, or any pro- tected place on the car near the battery. Any marking systems would be suitable but the following methods are suggested. Numbers are preferable. 1.260 —4 1.265 —3 1.270 —2 1.275 —1 1 .280 no mark or 0 1.285 +1 1.290 +2 1.295 +3 1.300 +4 Should all indications show that the battery is O. K., advise the owner to disconnect the battery at the end of a run. best the gravity and again the next day before starting out. This will clearly indicate whether the fault is in the wiring or inside the battery. Copyright 1922. B. B. Burling Bruce. Milwaukee, Publishers m tarn m . iw&m c Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair job A-14— BATTERY DIAGNOSIS PRIOR TO OPENING UP Object — To become familiar with the ear marks of defects without opening the battery. Apparatus — High rate discharge tester, hydrometer, voltmeter 0-3-15 range, charging apparatus and six volt battery giving trouble. Method 1. Place the battery on charge at the normal rate. 2. Watch the gravity closely in the separate cells. Record these and voltmeter readings, noting any increasing difference. The cell which is “slow to come up” should be regarded with suspicion. 3. Charge until the gravity ceases to rise, even though the gravity is not the same in all cells. Open the circuit and test with a voltmeter. Repeat at fifteen minute intervals, taking also gravity readings for one hour, or until the condition of the battery is determined. 4. In case of doubt or as additional check, take a “high rate test” using tester made for this pur- pose. If there is a variation of .1 volt or more per cell it indicates that the low cell is defective. 5. If tests show cells in good condition equalize acid, wash outside of box with soda, and place in clean place to note if any of the jars are leaky. Continue the charge to thoroughly mix the electro- lyte. Charge for at last five hours at one-half normal rate to insure reduction of sulphate and mixing of electrolyte. Questions 1. Before removing a battery from a car, what should be done? 2. Why is it necessary to fill cells with distilled water before charging? 3. If all terminal markings are removed how would you determine the polarity ? Two or three methods. 4. How would you test for a broken terminal Theory — The hydrometer diagnosis is by far the most suitable for unskilled help although the car owner may note various symptoms of a “sick” battery, namely : 1. Lamps not bright. 2. Horn not so loud as usual. 3. Lamps burn dimly after being on some time. 4. Motor turns engine over slowly or not at all. The causes of low gravity are several : 1. Internal short due to accumulated sediment or broken separators. 2. External short circuit in the wiring system of the car. 3. Leaky jars. 4. Sulphation. The preliminary tests are to determine whether the cause of low gravity is internal or external. It is assumed that the owner has tested his circuits as indicated in the “curb service.” In making all hydrometer tests remember that the middle cell is likely to show a lower gravity because of higher temperature. This cell will also show “low acid” due to evaporation before the others. Because of this, absolute uniformity of gravity is seldom possible. The variation in “gravity” should not exceed 20 points. Thus, “gravities” of 1.285, 1.275, and 1.295 in the three cells respectively are sufficiently uniform for practical purposes. Under a cell “high rate” discharge, the cells should be each discharged only a few seconds. The voltage indicator will generally show between 1.4 and 1.6 volts, depending on the size of the cell. Each cell of a battery should, however, indicate the same voltage. Fig. 8. A battery high rate tester is also made to test the entire battery. The theory of this tester is that if any cell is down the entire battery should be overhauled. It is quicker to make a complete test in one operation than in three or more. Fig. 9. The illustrations show the two standard pieces of apparatus for high rate discharge. Fig. 8. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-15— THE CADMIUM TEST ON CHARGE AND DISCHARGE Object — To become acquainted with the test which is universally used by manufacturers to indi- cate the individual condition of the pos. or neg. plates. Apparatus — Charging equipment, voltmeter, cadmium stick, six volt battery. Method 1. See that the battery is fully charged. 2. Run a discharge test at about the three hour rate taking voltage between Pos. and Cad., Neg. and Cad., and Pos. and Neg. plates. Fig. 10. Fig. 10. 3. Run a charge test taking like readings at least every 15 minutes until charged. 4. Plot the voltage and cadmium readings for charge and discharge. 5. Study the details of the curves and discuss in the write-up the condition of the pos. and neg. groups of each cell. Questions 1. Could a cadmium test be used to lessen the long over-charge many times resorted to in order to insure a charged battery? Why? 2. How would you use a cadmium test to determine whether or not the acid is weak due to slop- page or sulphation ? 3. When a battery is repaired by installing new positive groups, how could the test be used to indicate whether or not the battery was ready to be placed in service? Theory — Whenever the voltage of a cell is taken, it is self-evident that this reading includes the condition of the pos. plates -f- the condition of the neg. plates. The electrochemical condition of the plates we call potential. The cell voltage therefore becomes the pos. potential -j- neg. potential or pos. -J- neg. voltage. Cadmium in the commercial form has a potential or individual voltage of almost zero. The voltage between this element (cadmium) and any other element would naturally only indi- cate the potential of the one inasmuch as the pressure of cadmium is zero. The cadmium test is not always essential although there is considerable satisfaction in knowing the exact condition of the Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair plates. The negative test will invariably show where the fault lies, unless the cell is shorted. The negative plate seems to be more susceptible to sulphation than the positive. The cadmium stick should always be kept wet so as to insure reliable data. The “stick” is covered with perforated rubber so as to insure against making electrical contact with the plates and still come in contact with the solution. When taking cadmium readings insert the “stick” in the vent so that it will come in contact with solution. (Fig. 10). From the data taken it will be noticed that when the cell is discharged the voltages may be represented by diagram II, while when fully charged by III. (The numbers indicate the approximate conditions of a new cell.) Discharged -+■ — CD -L8 - a os - II. .25 Charged + CD -a.5- 15 2 65 - III. In II the pos. and neg. plates are -j- to the cadmium and in III the neg. plate has changed its rel- ative position and is — to the cadmium. It will further be noted that if the neg. plate is -f- to the cadmium or close to it in voltage the cell should receive a longer charge. As all voltage readings depend somewhat upon the rate of charge or discharge, always compare readings at like rates of current. Note: In all battery work it must be remembered that seldom should one test determine the con- dition of the battery, but two or more tests using different methods. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A- 16 — TESTING BATTERY JARS Object — To find out different methods of testing jars for “leakers.” Apparatus — Several jars which have proven defective, vibrating spark coil, magneto ringer, and 110 volt lighting circuit. Method 1. Strike several jars which are defective and determine to what extent a sound test can be used. 2. Fill a jar with water and set in water. (Keep the top of the jar dry). Test with magneto ringer with one terminal inside and one outside. Note results. 3. Try the same test on a six volt battery to detect a broken jar. State the advantages and dis- advantages of such a test. 4. Repeat tests 2 and 3 using a spark coil and battery. Explain results. 5. Repeat tests 2 and 3 using the lighting circuit. Make connections as shown in Fig. 11. Ex- plain results. Questions 1. Which of the above methods of testing single jars proved the most satisfactory? Why? 2. Which proved the most satisfactory in testing battery when assembled? Why? 3. When a battery is in service what conditions indicate a broken jar? Theory— It is generally not difficult to locate a leaky cell if the cause has been freezing. Usu- ally such a leak will be sufficient to cause a visible lowering of electrolyte in the jar and the sub- sequent moistening and rotting of the box. The principle most used in locating leaks is simply that acid is conductive. If the cell has been filled with acid some of the electrolyte has penetrated the jar through the crack. This thread of moisture is a sufficiently good conductor to permit satisfactory testing on the lighting circuit. Manu- facturers usually detect a crack by the sound when the jar is struck. This is probably accurate enough from their standpoint, but this method will not detect a pin hole leak. No test, no matter how good, will take the place of observation of conditions. The tests should be used as a last resort when observation has failed. It would be advisable to have a suitable testing method or device in every station and not rely entirely on observation. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers on ' ' y " ■ m Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-17- HOW TO OPEN A LEAD STORAGE BATTERY Object — To find out the different methods used at service stations in opening up a storage battery. Apparatus — Two six volt batteries of different makes, brace and bits, steamer, heated putty knife, and brush. Method — (Note the time required to perform the operations of opening a cell). 1. Clean the top of the battery with a stiff brush. Use water or gasoline if necessary. Vents must be closed. 2. Make a sketch of the strap connections on a tag and fasten same to handle. 3. Drill through the connector straps as indicated in Fig. 12. It is better to do this work with the battery on a low bench and in a tray to collect all the lead chips. See Fig. 13 and Fig. 14. 4. Remove connector straps as indicated in Fig. 15 being careful not to injure jars or wooden case. Fig. 16. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers ; . Ill Fig. 12. 1 Fig. 13. Fig. 14. 5. Place in steamer as shown in Fig. 16 until the sealing compound has softened. If necessary, heat the putty knife and loosen the sealing compound one cell at a time. 6. Try the putty knife without steaming. Loose Leaf Shop Mannal Burling Vocational Series Battery Testing and Repair 7. Hold the battery in “floor clamp” Fig. 18 and with the aid of two pliers or tongs raise element and drain. See Fig. 17 for correct position when raising element. Remove cover, Fig. 19. 8. Permit the elements to drain a few minutes. Fig. 20. Fig. 17. Fig. 18. Fig. 20. Theory — Among the commercial methods used in opening batteries are the following: 1. The use of a hot knife to loosen the sealing compound. This method is effective when only a small quantity of compound is used. 2. Hot running water run into the vents until the compound is softened sufficiently. Although not a rapid method is satisfactory where large quantities of water are available. 3. Steam run into the cells through the vents is a popular method and probably the best for the average service station where all varieties of cells are repaired. 4. External heating by flame is not as satisfactory because the flame burns the compound giving off black smoke and does not heat uniformly. 5. External heating in an oven has the disadvantage of cost if an electric oven, and difficulty of knowing when the compound is softened sufficiently. Note: Never try to pound the terminals loose as such rough treatment is sure to weaken the connection between plates and connecting strap and between active material and the plates. If ter- minals cannot be easily removed drill through and soak in soda water. It is always considered wise to have the owner present when the battery is opened. Copyright 1922, B. B. Burling Bruce. Milwaukee. Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-18— WINTER STORAGE Object — The object of the test is to become familiar with different methods of storing a battery. Apparatus — One or two six volt storage batteries, suitable means of charging. Method In order to become familiar with the various methods of storage, the battery should be opened and each cell tested differently. The value of this method is two-fold. The test will show a comparison of the different ways of storage as no other test can and also the detailed method of procedure in each case. 1. Charge the batteries until fully charged. 2. Open up the battery and prepare one cell for storage by method No. 2 (wet storage). (See Theory). 3. Prepare one cell for storage by wet method No. 3. 4. Prepare one cell for storage by dry method No. 1. 5. Prepare one cell for storage by dry method No. 2. 6. Reassemble the cells after the plates are dry. Charge in series keeping close watch on tem- perature, gravity and voltage. Questions 1. Which method of wet storage brought the plates back quicker? Explain all details of test. 2. Which method of dry .storage kept the plates in best condition? 3. Which group of negatives heated the most? 4. Which method of dry storage brought the cells up to charge in the shortest time? Theory— Storage is necessary when the auto, is to be laid up for some time especially in the winter. A battery gradually discharges and is liable to freeze if neglected. How to store a battery, and how to determine which method to use, are questions which always arise. In general, dry storage should be used when a battery in all probability will require attention in a short time, or if it is to be left in storage for three or more months. Wet storage is less costly and is generally used. (Use high rate test to determine condition of battery before deciding on the method to use). Wet Storage No. 1 (a) Charge, (b) Place on rack with instructions to give a freshening charge every month. (Keep gravity up to normal). No. 2 (a) Charge, (b) Empty out acid, (c) Wash out sediment, (d) Fill with fresh water, (e) Place on shelf until needed, (f) When needed a bench charge is necessary after filling with 1.310 acid. No. 3 (a) Charge, (b) Empty out acid, (c.) Wash out sediment, (d) Place in cool place until needed, (e) When needed fill with 1.300 acid and charge. No. 4 (a) Charge on bench until fully charged, (b) Place on storage bench where the battery is connected in series with others and the charge continued at .1 amp. continuously until needed. In order to regulate the current connect incandescent lamps in series with the battery. Note: Of these methods probably No. 4 is the best where suitable D. C. is available because less handling is necessary and the battery can be had on short notice. Method No. 2 has many points in its favor and is better than No. 1 or No. 3. In all acid storage fill with water every two months. Dry Storage No. 1 charge, open up battery, take out elements, separate groups if possible, and set in water over night, set groups out to dry. When negative group heats, dip in water and set out again to dry. In reassembling use new separators and charge at one-half normal rate. No. 2 charge, open up battery, empty out acid, fill with water, let stand over night, empty and fill with fresh water, short circuit the battery for one hour, remove the groups to dry. In reassembling use new separators and charge at one-half normal rate. Note: In disassembling a battery always make a sketch in chalk on the box or on a tag showing detail of strap connection. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers & i^ir a Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-19— MINOR DEFECTS AND REPAIRS Object — To take care of repairs which will require little time and expense. (24 hours service). Repairs which do not involve the plates. Apparatus — Battery with broken jar, battery requiring new separators, corroded terminals. Method 1. Fill the jar which is to be removed with boiling hot water and allow to stand about five minutes. Remove the jar as shown in Fig. 21. 2. Fill the new jar with boiling hot water at the same time the old jar was filled. The rubber will be soft and pliable when ready. A flame is sometimes played on the outside of the jar instead of using hot water. The only possible disadvantage of this method is that the jar is not usually heated uniformly. Fig. 21. 3. Replace the old jar after the inside of the box has been oiled with vaseline and the jar warmed. 4. In replacing separators care should be taken that the grooved side is against the pos. plate. The circulation which this will bring to the surface of the pos. plate will increase the life by remov- ing any organic acid present in the wood. 5. Wash all corroded terminals and place all loose parts in soda water until clean. Questions 1. What instructions would you give to a battery owner in order to avoid the external defects noted ? Copyright 1022, B B Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair 2. What instructions would you suggest to avoid the occurrence of the internal defects? 3. What causes a terminal to break off? 4. Under what conditions can the repairs be taken care of away from the service station? 5. Under what conditions should a battery be sent to a service station? Theory — The vital part of any storage battery is the plates. Troubles located in or vitally effect- ing these vital organs will be handled later. Minor defects are considered as all troubles which occur externally and internally, still not materially affecting the plates. External defects are caused largely by improper watering cells. Over flooding will start cor- rosion of terminals, rotting of box, and eating away of the metal parts of the car surrounding the battery. These defects are of minor importance if their influence is not extended to the inside of the cell. In order to avoid such danger, frequent watering and not too much at any one time should be the policy. Corroded terminals may be avoided by coating the top of the battery and terminals with vase- line. Should they become corroded wash off with solution of washing or baking soda. Many times cable terminals which cannot be easily removed can be loosened in a few minutes by applying soda water. Acid soaked boxes should be so treated with soda and when dry coated with acid proof paint. Internal Minor Defects — Separators of wood must be treated to remove injurious organic chemicals from the fiber. Many such organic substances are oxydizing agents and when present in a cell eat away the lugs, grids, and connecting straps of the positive group. Any cell which shows such corrosion is evidence that “raw” or improperly treated separators were used when the cell was last assembled. Whenever new separators are added to a cell and foaming is noticed on charge, it is evident that the “curing” has not been thorough. Under such circumstances empty out the acid at the end of the charge and replace with fresh electrolyte. This precaution should prolong the life of the battery con- siderably. The separator is the weakest part of the cell and it is important that good reliable ones are used in any repair work. Separators fail because of heating, strong acid, and buckling of pos. plates. Hard wood or rubber costs more than bass wood and also offers a greater resistance to the elec- tric current, but the prolonged life of the cell will more than repay for the additional cost. In all repairs where the plates are exposed to the air, the work should be done as quickly as possible as drying will heat and injure the negative plates. Should the plates require attention the policy is generally to separate the plates if shorted and then place on charge until the plates are in normal condition. This will soften the material and per- mit pressing if need be. Fig. 22. In case only one cell is to be inspected, drill through the connectors at the ends farthest from the cell to be opened. If the middle cell is to be inspected, drill into terminal posts marked X, Fig. 22. This method is always desirable because a complete inspection of a six volt battery can be made with only two drillings. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-20— LEAD BURNING Object — To learn the methods used in welding lead to lead. Apparatus — One or more of the following apparatus : 1. Oxygen and Acetylene. 2. Hydrogen and Oxygen. 3. Illuminating gas and oxygen. 4. Electrical A. C. low voltage. 5. Electrical D. C. low voltage. 6. Soldering flux (non-corrosive). r~ i i. < < — w ^ 1 1 Fig. 24. 1. Examine each piece of apparatus (Fig. 26) carefully before lighting flame. 2. When confident of knowing the operation of the system, prepare two lead straps by cleaning with “file card” or shave hook. Fig. 23. Place the two straps on a sheet of iron in the position desired. Fuse the two by playing the flame carefully along the line of intersection. During this pro- cess add a little lead of the same composition as the strap. See Fig. 24. Block up sides of strap to prevent running away of molten lead. Fig. 25-a. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair 3. Burn in a new plate where one has been removed. This is done by cutting a slot with a hack saw in the plate connecting strap the width of the conducting lug of the plate. Figs. 25-a and b. Clean thoroughly and wash with soda water, if found necessary, before burning. 4. Burn a strap with alternating current low voltage. Fig. 28. 5. Burn a strap with direct current low voltage. Figs. 29 a, b, and c. 6. Set up a burning rack and burn on new plates. Figs. 30a and b. 7. Solder cable to terminal lugs (“tinning” and “sweating”). Questions 1. Compare the time required by each method of burning. 2. In which gas line should the water valve be connected? Why? 3. When burning on a post or working with a flame around a battery, why should the vent plugs be removed? 4. Why is it necessary to heat to melting point both surfaces to be welded before allowing molten lead to fill in? 5. Explain in detail the operations of soldering a cable to a terminal lug. 6. Why are terminals lead burnt and not soldered? 7. Why are terminals lead burnt and not bolted? Theory — “Lead burning” is the fusing of lead without the aid of other metals which melt at a lower temperature. Soldering is the joining of two metals with the aid of a lead alloy, of lower melt- ing point than the metals being soldered, and a cleaning flux. Burning may be done with a heated carbon point or with a pencil pointed flame. Commercially the flame is produced by hydrogen-oxygen, acetylene-oxygen or illuminating gas- oxygen. The water valve “A” in Fig. 26 is of utmost importance because a “back flash” would be liable to cause a disastrous explosion. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair If too large a flame is used, the entire lead is likely to melt and run away unless confined in a mold, or by retaining strips of carbon or iron placed on the sides of the “work.” All heavy work such as extending posts, connecting bus bars, etc., can be done with a large flame. The smaller the work the smaller the flame. Fig. 27 shows a typical flame with the hottest portion indicated. Always use the concentrated hot point except where a general heat is desired. For light work an electric hot point is sometimes used, although the method is likely to prove quite expensive especially where the energy is from a low voltage battery. Fig. 28 shows the most econo- mical electrical method although the apparatus shown in Fig. 29 is good for an emergency. In any method it is of utmost importance to fuse the surface of the work before building the post, lug, strap, etc. Clean with shave hook as shown in Fig. 30c. Only add molten material from the “burning stick” when the surface to receive it is molten. If the terminal is lead coated copper do not use a shave hook for cleaning, but use soda and scratch brush. Never use a flux in burning. Soldering is seldom resorted to, although if terminals of repaired batteries show exposed copper or brass, the same should be retinned before being replaced. Fig. 30-c. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-21— MAJOR DEFECTS AND REPAIRS. Object — To detect causes and to repair a battery when the source of trouble is in the plates. Apparatus — Battery to be repaired, lead burning outfit, steamer, battery plate press, high rate tester, voltmeter and hydrometer. Method 1. Charge the battery over night. 2. Examine each cell to locate source of trouble. 3. Continue charge another day if it is thought that the cells would “come up.” 4. After the battery is charged as much as possible, blow out gas in each cell, then remove straps and covers by methods already known. 5. Remove all shorts between plates and replace for recharge, if necessary. 6. Separate the -)- and — groups and press separately in the press to straighten buckled posi- tives and bulged negatives. Fig. 31. Fig. 31. 7. Reassemble the elements with new separators. 8. Place in cells with new electrolyte of 1.300-1.310 gravity. 9. Place on charge before sealing if there is any doubt as to the condition of the plates. 10. If battery charges up properly seal with asphaltum, Figs. 32, 33 and 34. The flame is playea on the surface to make the sealing more perfect on the jars and terminal posts. Theory In making major repairs on a battery, it is to be remembered that the positive plate is the weaker and should be handled with great care. Should the plate crack in being straightened, the plate and Copyright 1922, B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair possibly the entire group should be discarded. In straightening any group of plates, spacing boards should be placed between the plates. The negative material is generally soft and is therefore more easily pressed into shape. Before any internal work is done on a battery, the plates should be reduced to as good a con- dition as possible. This preliminary charging softens the active material and makes the work easier on the plates, as well as for the operator. Plates which have once been buckled will warp very easily again. Replace the old separators with good hard wood ones and increase the charging rate on the car slightly, because a semi-charged battery will buckle very quickly. Over-charging raises the temperature and softens the active material. Undercharging hardens the material and buckles the positive plates. In most service stations the straightening of the positive plates is never done. Slightly buckled plates may be returned to service but never those badly distorted. Copyright 1922. B. B. Burling Bruce. Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-22— INSTALLATION OF NEW OR OLD BATTERY Object — To know the points to be taken care of, especially in re-installing a battery after repairs. Apparatus — A battery which has been repaired and an auto which is in garage or repair shop. Method 1. See that the battery is located where it is accessible for testing and adding water. 2. The battery compartment should be ventilated and means for draining should an accident occur and spill the battery. 3. The battery should rest on cleats which allows an air space on the bottom. 4. See that hold downs grip the handles firmly. No cleat or hold down'strap across the top of the battery should be permitted. 5. The compartment should be free from oil, water, dirt, or tools and be kept dry at all times. 6. Wash out box with soda water, if the installation is in an old car. 7. Coat the terminals with vaseline or heavy grease after the terminal connections have been made. 8. Readjust the charging rate in accordance with the conditions found inside the cells. If there was found considerable shedding of active material from the positive plates, reduce the rate two to four amperes. If there was a buckling of the plates and the active material hard, increase the rate two to four amperes. Excessive charging is just as bad as under charging. A battery has to undergo such a variety of treatments that it is impossible to give detailed instructions on rates of charge. Follow instructions given on the battery. Questions 1. How can you determine when a battery is placed in a car in the right position? 2. What is liable to happen if the battery is not rigidly secured in position? Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-23— CARE OF A STORAGE BATTERY. Object — To review much of the material which has previously been given on the subject in this text and elsewhere and obtain detailed information on the care of a lead storage battery. TO BE REMEMBERED Installation 1. Accessibility of battery. 2. Ventilation of compartment. 3. Battery securely fastened in place. 4. Compartment free from foreign material. 5. Neutralization of acid with soda. 6. Protection of terminals with heavy oils or grease. 7. Terminal lugs securely fastened to battery terminals. 8. Proper charging rate. Bi-weekly inspection 1. Pure water added periodically (two weeks or less) to proper height. Never add acid. 2. Test with hydrometer. Record results. Never below 1.150 sp. gr. 3. Temperature test at the end of normal run. 4. Test connections. 5. Neutralize acid with soda. Note cause of sloppage and try to prevent same. 6. Coat terminals with vaseline or grease. Special Instructions 1. Never bring lighted match or torch near charging battery. 2. Charge with direct current always. 3. Connect (-)-) positive charging wire to (-)-) positive terminal of battery. 4. Charge should always be continuous unless the temperature rises above 105° F. 5. Should battery show internal trouble have repaired immediately. 6. Have acid equalized in the fall of each year before freezing temperatures injure the battery. CAUSES OF BATTERY FAILURE WHILE IN SERVICE 1. Open in generator circuits, causing ammeter to always indicate discharge. 2. Loose connection in generator circuit or slipping belt causing the ammeter to fluctuate con- siderably, possibly registering discharge. 3. Short circuit in battery system. 4. Excessive night running with all lights on. 5. Cut-out not set right or not operating properly. 6. Much very slow driving at night. 7. Using car for short runs where battery cannot recover from the loss sustained in starting the motor. 8. Corroded terminals (poor contact). 9. Ignition switch left “on” when not using car. 10. Internal short due to buckled plates or sediment. 11. Impurities in the battery causing “local action” or “local discharge.” Questions 1. How often should inspection be made in winter? 2. How often should inspection be made in summer? 3. When should water be added in winter? 4. How much water should be added? 5. What effect would the wet top of cells have? 6. What action has the acid on the terminals? 7. Which terminal is corroded most? What is the color due to corrosion? 8. What is sulphation? 9. Which group of plates is most likely to become sulphated? 10. How is sulphate reduced? 11. What are causes of buckling? 12. What effect does charging have on sulphation? Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair 13. What is the cause of sediment at the bottom of cells? 14. Should no distilled water be available, what water could be used? 15. Should the temperature rise above 105° F when charging on the car, what does it indicate What can be done to prevent such a condition? 16. Can you suggest any improvements which you think would give longer life or greater serv ice to the storage battery? 17. When would you consider it necessary to replace the acid in a battery? 18. What is the cause of grids cracking? 19. What is the cause of plates growing? 20. What is the cause of loss of active materiel? 21. What is cause of negatives becoming “mossed”? 22. What is the cause of negatives becoming swelled? 23. What is the result of age on the negative plates? Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-24— TESTING AND REPAIR EQUIPMENT, SHOP ARRANGEMENT, ETC. Object — To give the student first-hand information on shop practice. Equipment Testing 0-30 range ammeter 0-3-15 range voltmeter Cadmium test terminals High rate discharge tester Syringe hydrometer Thermometer Hydrometer syringe for adding water to cells Jar tester Suitable battery charging outfit with proper current regulators. Repair Battery steamer Battery press Bench vise Hydrogen-oxygen lead burning outfit Carbon arc burning outfit Floor battery vise Plate burning stand Single gas hot plate Sealing compound heating pot (coffee pot) Separator cutter Sink Water Still if local water is not suitable Work bench (lead covered) Charging bench Storage rack Stock bins for repair parts Storage tank for separators Mold for casting lead burning bars Flat trays for disassembled battery parts Non-corrosive soldering flux for terminal soldering Hand Tools Brace and bit 54”, %” Wire brush Coarse file 10"-12" Vixen Hack saw Hammer (ball) Bristle brush Bellows Putty knives 1" wide Gas pliers Flat nose tongs Paint brush Large end cutting pliers Scraper Wrenches Screw driver Center punch Coarse back saw blades File brush 3/16", Y\" , 54 ”, V 2 " wood chisels Gasoline torch Supplies 1 — Carboy 1.300 acid 1 — Carboy 1.400 acid Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Sealing compound Asphaltum paint Washing soda Method 1. Secure from catalogs and other sources the cost of the minimum equipment, tools and sup- plies listed. 2. Secure for personal use all available catalogs and bulletins covering the necessary apparatus. 3. Submit a report on cost and also a detailed sketch of the arrangement of shop or workroom which would secure economy of time and labor. 4. Submit a “Job Ticket” which would be suitable for battery service work. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A-25— ELECTRIC VEHICLE OPERATION Object — To know how the peculiar characteristics of a battery effect the operation of a vehicle. Apparatus — An electric vehicle (pleasure or commercial) if available. Method 1. Install an ampere hour meter on electric vehicle. 2. Discharge under service conditions at various points on controller and note total mileage obtained under each test. 3. Note the action of the car (speed) when nearing the end of run. 4. Plot a curve between mileage and points on controller. Questions 1. If there were no ampere hour meter on the car, how would you know the approximate con- dition of the battery? 2. Is there any real danger of being stalled in an electric vehicle if the driver is familiar with the use of the electric car? Why? 3. What conditions will be noticed when the battery is approaching discharge? 4. How should the battery compartment be cared for so as to avoid corrosion of metal parts and rotting of the wood? 5. If a car becomes stalled and additional mileage is made after standing a while, what would the effect be upon the battery? To what extent would you consider this injurious to the battery? 6. On which point of the controller can the greatest mileage be obtained? Copyright 1922, B. B. Burling Bruce. Milwaukee. Publishers Loose Leaf Shop Manual Burling Vocational Series Battery Testing and Repair Job A- 26 — CHARGING EQUIPMENT Object — To compare the efficiencies of commercial charging units. Apparatus — Motor-generator, mercury vapor rectifier, magnetic vibrator rectifier, “Tungar” or heated cathode rectifier, rotating commutator rectifier, two wattmeters, or other suitable testing instru- ments and a storage battery. Method 1. Examine each piece of apparatus carefully noting all name plate information. 2. Obtain catalogs from companies manufacturing charging apparatus. 3. Set up each charging set with wattmeters and battery. Calculate the efficiency at low and high rates of charge and discharge. Questions 1. Which apparatus seems most adaptable for a small services station? Why? 2. Which apparatus seems most serviceable for a large station giving night and day service? Why? 3. Which proved to be the most efficient for single battery charging? 4. Would the efficiency be the same if more batteries were charged at one time? Explain in detail. 5. Calculate the cost of charging a 60 ah 6 v. battery for 24 hours at 6 amp. rate. Use the effi- ciencies for each of the above rectifiers as found by actual test. 6. Determine the first cost of the various charging equipment from the manufacturers. Theory Motor-Generator, as the name indicates, is a combination of a motor and a generator belted or connected together on the same shaft. The average efficiency of this type of charging is lower than some other types, but as it is possible to get such a set in any capacity desired, most of the large service stations are so equipped. Cost of upkeep is very low. Mercury Vapor Rectifier has a high efficiency, although the upkeep cost in bulb replacement is considerable. This type of rectifier makes use of the complete alternating current wave, which is rectified at the voltage desired. “Tungar” or Heated Cathode Rectifier eliminates much of the cost of upkeep of the Mercury Rectifier and operates at approximately seventy-five percent efficiency under normal load. The fact that it will automatically stop and start when the alternating current is interrupted without any com- plicated relay system, has won for itself a place in small service stations, where there is no night attendant. Bulb cost about lc per hour of service. Rotating Commutator Rectifiers have been placed on the market and, although inclined to be a little noisy, when the commutator becomes pitted, can be adjusted to deliver direct rectified current, at a full load efficiency of about 80-83 per cent. Under heavy loads, excessive sparking will result and cooling fans are necessary. Vibrating Magnetic Rectifiers are used to a considerable extent for charging one or two batteries because of the low first cost and upkeep. The efficiency is also high. For service station work, how- ever, its use is very limited. Copyright 1922, B. B. Burling Bruce, Milwaukee, Publishers