The Automotive Battery Construction and

After studying this chapter, you should be able to:

1. Discuss the construction and operation of a lead-acid storage battery. 2. Describe the chemical actions in the battery during charge and during discharge. 3. Define and discuss battery ratings. 4. Explain why battery terminal varies with temperature, charging rate, discharge rate, and state of charge of the battery.

24-2 CHEMICALS IN BATTERY 24-1 THE BATTERY The chemicals in the battery are sponge Battery (Fig. 24-1) supplies current to lead is solid, lead oxide (a paste), and operate the starting motor and the ignition sulfuric acid (a liquid). These three sub- system when the engine is being started. It stances are made to react chemically to also acts as a voltage stabilizer by produce a flow of current. The lead oxide supplying current for the lights, radio, and and sponge lead are held in plate prides to other electrical accessories ‘when the form positive and negative and negative is not handling the load. The plates (Fig. 24-5). battery is an electrochemical device. This The plate grid is a framework of means it uses chemicals to produce lead alloy with horizontal and vertical . The amount of electricity it can bars. The plate grids are made into produce is limited. As the chemicals in the plates by applying lead oxide paste. battery are “used up” the battery runs down, The horizontal and vertical bars hold or is discharged . It can be recharged by the paste in the plate. supplying with electric current from a After the plates are assembled into , or a vehicle alternator can the battery is given a “forming” recharge it. The “used up” chemicals are charge. This changes the lead oxide then returned to their original condition, so paste in the negative, or minus, the battery becomes recharged. plate to sponge lead. It changes the lead oxide paste in the positive, or plus plate to lead peroxide.

1 the internal connections are in place 24-3 BATTERY CONSTRUCTION the cover is put (Fig. 24-1 to 24-3). In In the battery, several similar plates many batteries, the cover has are properly spaced and welded, or openings through which liquid can be lead-burned , to a strap. This forms a added water; the filler plug or vent plate group. Plates of two types are caps are removed. After the liquid is used, one for the positive plate added and the battery is given an group, the other for the negative initial charge. It is ready for operation plate group. A positive plate group is Maintenance-free batteries have no nested with a negative plate group. vent caps Separators are placed between the plates to form an element (Fig. 24-3). The separators hold the plates apart so that they do not touch. At the same time the separators are porous enough to permit liquid in circulate between the plates. Wooden sheets, spun glass matted into sheets and porous sponge rubber sheets have been used as separators. Late- Fig.24-2 phantom view of a 12- model batteries have separators battery with the terminals in the made of acid-resistant polyvinyl state of the battery (Division of chloride on polyethylene saturated General Motors Corporation). cellulose.

Fig. 24-1 Two types of automotive Fig.24-3 Partly cut away and batteries. The left battery it caps disassembled 12-volt battery(Ford which can be removed to check the Motor Company) battery state charge and add to Some batteries have the two main water. If needed the right battery with terminals on the battery cover as in side terminals is a sealed 24.3. Other batteries have the maintenance free type and requires terminals in the side of the battery no water. The charge indicator in the (Ford Motor Company) cover as in top shows the state of charge of the Fig 24.3 Other batteries have the battery. terminals in the side of the battery The elements are placed in cells in case as in Fig 24.2 Figure 24.4 the battery case. Then heavy lead shows how the cables are connected connectors are attached to the cell to a side terminal battery. It also terminals to connect the series. After shows the battery-mounting

2 arrangement. On a top-terminal battery (Cadillac Motor Division battery the positive terminal (or of General Motors Corporation) from “post”) is larger than the negative the terminal where chemical activity post. has collected them. They now Many batteries are the through the circuit to the other from maintenance-free type. They require terminal where the chemical activity no special attention expect for an has removed them. Chemical occasional check of the connections activities now begin again so the tire and the built-in charge indicator (Fig 2-volt pressure is maintained. The 24-1 right) other batteries have vent current now continuous. The caps (Figs 24-3 and 24-4), which can chemical action use up the sponge be removed. Then you can look lead, lead peroxide and sulphuric down into the battery cells to see acid. After a certain amount of whether they need water. Also a current has been withdrawn the hydrometer can be used to check the battery is discharged (“run down or battery charge. dead”). It is not capable of delivering any additional current. When the 24-4 CHEMICAL ACTIONS IN battery has reached this state, it may BATTERY be recharged. This is done by The liquid in a battery is called the supplying it with a flow of current . It is made up of about 40 from some external source. The percent sulfuric acid and about 60 external source forces current back percent water (in a fully charged through the battery.This reverses the battery) when sulfuric acid is placed chemical activity in the battery.The between the pieces chemical actions plates are restored to their original takes place. These actions removed composition and battery becomes electron from one group of plates recharged.It is then ready to deliver and collect them at other. This additional current. creates a pressure of 2.1 The Chemical action that take place between the two terminals of the are rather complicated.The sponge battery cell. If any circuit no connects lead(negative plate) and lead the two terminals, no further peroxide(positive plate) change to chemical activity takes place. lead sulphate during the discharge However when the two terminals do process.The sulphate comes from become connected by an electric sulphuric acid. The electrolyte loses circuit, electrons (current will flow. acid and gains water as the sulfate goes into the plates. Therefore discharging the battery changes the two different chemicals in the battery pieces to a third chemical lead sulfate. Recharging the battery changes the lead sulfate back to They flow Fig 24.4 Cable sponge lead in the negative plates, connections for a side-terminal and to lead peroxide in the positive plates. Meantime the sulphuric acid

3 reappears in the electrolyte of the compare hour compare. This is the battery. amount of current time a battery can deliver for 2v hours witness the cell 24-5 CONNECTING CELLS voltage dropping below 1.75 volts Automotive batteries are usually 12 with a electrolyte temperature 80 0F volts: units. There are six cells in the 26.7 0C. For example battery that can 12-volt battery. The six cells are deliver current of 5 amperes lo: 20 connected in series. In series hours is rated as having a 100. connections, the add. Some amperes hour capacity 120x5= 100 special applications use 24-volt batteries: these special-purpose 3.Cold Cranking Rate- One of the batteries have 12 cells. two cold-cranking rate if the number Although a battery cell at 80 0F will of appears that a battery can deliver test on open circuit about 2.1 volts for 30 spreads when at OFF 178’C when fully charged common practice without the cell volt ages ladling is to cell 2 volts. Therefore a six-cell below 1.2 volts. A typical rating for a battery is said to be a 12 volts battery with a reserve capacity of battery rather than a 12.6 volt 125 minutes would be 430 amperes. battery. This figure indicates the ability of the battery to : the engine at low 24-6 BATTERY RATINGS temperature. The second cold- The amount of current that a battery cranking rate is measured at – 20 0F can deliver depends on the total area – 28.9 0C. In this the final voltage is and volume of active plate material. allowed to drop to 1 volt per cell. A It also depends on the amount and typical rating for a battery with a strength of electrolyte. This is the reserve capacity of 125 minutes percentage of sulfuric acid in the would be 320 amperes. electrolyte. Factors that influence battery capacity – its ability to deliver 4.Watts Delco- uses an additional current – include the number of rating – watts. This is roughly plates, the cell size, and the quantity equivalent to the battery cold- of electrolyte. The ratings most cranking rating. commonly used in referring to battery capacity are discussed 24.7 BATTERY EFFICIENCY below. The ability of the battery to deliver current varies within wide limits. It 1.Reserve Capacity- Reserve depends on temperature and rate of capacity is the length of time in a discharge. At low temperature minute that a fully charged battery at chemical activities are greatly 80 0F can deliver 25 amperes. A reduced. The sulfuric acid cannot typical rating would be 125 minutes. work as actively on the plates. This figure tells how long a battery Therefore the battery is less efficient can carry the electrical operating and cannot supply as much current load if the alternator quits. for as long a time. High rates of 2.Ampere Hour Capacity- An older in discharge will not produce as many the 20-hour rate also called the ampere-hours as low rates of

4 discharge. At high discharge rates c. Decreasing temperature. Lower the chemical activities take place battery temperatures resource a only on the surfaces of the plates. higher voltage to maintain charging They do not have time to penetrate rate the plates and to use the materials 2. The terminal voltage of a battery below the plate surfaces. The chart that being discharge decreases with: below relates battery efficiency to a. Increasing discharge rate. As the battery temperatures. However these rate of discharge proof or chemical are only approximations. activities increase and cannot penetrate plates so effectively. Therefore voltage reduced. Efficiency Battery b. Decreasing state or charge. With Percent Temperature less of the active mate takes place Deglees F(C) and voltage drops. 100 80|[26.7] c. Decreasing temperature. With 65 32[0] lower temperature the chemical 50 0[-17.8] activities cannot go on as effectively 10 -45[-42.8] and the voltage drops.

24-8 VARIATIONS IN TERMINAL BATTERY MAINTENANCE AND VOLTAGE SERVICE Because the battery produces voltage by chemical means voltage 24-9 BATTERY MAINTENANCE varies according to a number of Complete battery maintenance includes conditions. These conditions and the following: their effect on battery voltage may be summed up as follows 1. Visually check the battery. 1. Terminal voltage pattern being 2. Check electrolyte level in cells charged increases with on batteries with caps. a. Increasing charging rate. To 3. Add water if the level is low (vent- increase charging rate (ampere cap batteries). input) the terminal voltage must go 4. Clean off corrosion around up. battery terminals and from top of b. Increasing state of charge. As batteries with top terminals (Fig state of charge goes up voltage must 24-3) go up to maintain charging rate For 5. Check battery condition by example a voltage of approximately testing its state of charge 2.6 volts per cell is required to force (explained later). a current through a fully charged 6. Recharge battery if it is low. battery. This is the reason that voltage regulators are set to operate 24.10 CAUTIONS FOR BATERY at 15 volts – slightly below the SERVICE voltage required to charge a fully These are the important cautions to charged battery. This setting protects observe when working with batteries the battery from overcharge.

5 1. The sulfuric acid in the electrolyte battery terminals and tops missing is very corrosive. It can destroy vent caps and loose or missing hold- most things it touches it will eat down clamps. Leakage causes white holes in cloth. It can cause corrosion on the battery carrier and serious burns if it gets on your surrounding metal parts. Leakage is skin. If it gets in your eye due to a crackled battery case or top. protection when working around The remedy is to install a new batteries. If you get battery acid battery. on your skin. Flush it out at once The top of the battery can be with water over and over Fig 2-12 crackled if the wrong wrench is used Then get to a doctor at once. to disconnect or install cable clamps 2. Gases form in the battery when it top terminals. The case can be is being charged. These gases cracked if the hold-down clamps are are highly explosive. Never light a over tightened. match or a cigarette when working around batteries. You 24.12 CHECKING ELECTOLYTE might cause an explosion that LEVEL AND ADDING WATER could seriously harm you. On vent cap batteries the electrolyte 3. The battery can supply a very level can be checked by removing high current. Never wear rings the caps, Some batteries have a spilt bracelets, watches or hanging ring which indicates the electrolyte necklaces when working around level (Fig 24.5). If the level is low add batteries. If a metal ring or other water. Some batteries have an ornament should accidentally electrolyte-level indicator (a “Delco short a battery a very high current Eye”). It gives a visual indication of will flow. This could turn the ring the electrolyte level (Fig 24.6). Black white-hot in an instant and you means the level is okay. White could get a serious burn. means the level is low. 4. When jump-starting a car follow the instructions and caution in 25- Careful : Do not add too much water. 9. A wrong step can damage the This can cause electrolyte to leak out electrical system and cause you and corrode the battery carrier and to get hurt. other metal nearby. 5. When disconnecting a battery always disconnect the cable from 24.13 CLEANING CORROSION the grounded the insulted OFF BATERY terminal or any terminal or wire On batteries with the terminals on that is hot (connected to the top the terminals and cable clamps insulted terminal you will not be sometimes corrode. This corrosion making a direct short across the can be cleaned off disconnecting the battery. clamps and cleaning the terminal and clamps with special wire 24.11 VISUAL INSPECTION OF brushes (Fig 24-7). Battery-top BATTERY corrosion can be cleaned off by Look for signs of leakage a crackled brushing the top with baking soda case or top corrosion buildup on solution. After the foaming stops,

6 flush off the battery top with water. Terminals can be coated with an anti corrosion compound to retard corrosion.

24.14 CHECKING BATTERY CONDITION On vent-cap batteries, the battery can be checked with a hydrometer to determine its condition. Other Fig 24.5 Appearance of the methods use testing instruments, as electrolyte and split ring when the explained later. These other electrolyte is too low and when it is methods are for the maintenance- correct (Delco-Remy Division of iree batteries but can also be used General Motors Corporation) of the on the vent-cap type. electrolyte (Fig 24.9). The height of the stem above the electrolyte tells 24.15 HYDROMETER TEST you the battery state of charge. Here The hydrometer tests the specific is what the readings mean. gravity of the battery electrolyte. 1.265 – 1.299 Fully charged battery There are two types of hydrometer 1.235 – 1.265 Three-fourths charged (Fig 24-8). One uses a series of 1.205 – 1.235 One half charged plastic balls, the other a glass float 1.170 – 1.205 One fourth charged with a stem on top. To use a ball- 1.140 – 1.170 Barely operated 1.110 type hydrometer, stick the rubber 1.110 - 1.140 Completely charged. tube in the electrolyte. Then squeeze and release the rubber bulb. This draws electrolyte up into the glass tube. The number of balls that float tells you the battery state of charge. If all ball float the cell fully charged. If none float the cell is discharged.

Careful : Do not drip electrolyte on the car or on yourself Electrolyte will damage the paint on the car and eat hole in your clothes. See caution 1 in 24-10

The float type hydrometer (right in Fig 24-8) has a float with a stem that sticks up above the electrolyte level in tubs. They float stem is marked to indicate the spare.

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Fig 24.7 Using battery terminal brush to clean the battery terminal posis and cable clamps Black Motor Fig 24.6 A battery cell with Division of General Motor electrolyte level indicator(top).The Corporation electrolyte at one correct level and(bottom)low electrolyte level.(Delco-Remy Division of General Motor Corporation).

If some cells test considerably lower than others, it means there is something wrong with those cells. It could be that a cracked case has allowed electrolyte leakage or perhaps there is internal damage to the plates or separators. If the variation is only a few specific-gravity points, then there is probably no cause for alarm. But if the low cells measure 50 points lower then those cells are defective and the battery should be replaced. Some 12-volt batteries for passenger have a slightly lower specific Fig.24-8 Battery hydrometers to gravity when charged For example check electrolyte specific gravity. one type is fully charged with a specific gravity of 1.270. Other batteries such as those used in hot climates have a specific gravity of 1.225 when fully charged. The decimal point is not normally referred to in a discussion of specific gravity. For example “twelve twenty twenty-five means 1.225 and eleven fifty means 1.150.

8 battery wears out and must be replaced. 24-18 LOSS OF SPECIFIC GRAVITY FROM SELF- DESCHARGE If a battery stands idle for a long time, it will gradually run down. This is due to the chemical actions between the electrolyte and the battery plates. The higher the temperature the more rapid this self- discharge. 24-19 FREEZING TEMPERATURE OF ELECTROLYTE Fig.24-9 Using a float hydrometer to check a battery cell. Reading must The higher the specific gravity of the be taken at eye level. The higher the electrolyte the lower the temperature float stem stick out of the electrolyte, must be before the electrolyte the higher the state of charge of the freezes. The battery must be kept battery. sufficiently charged in cold-weather to prevent freezing. Freezing may 24-16 VARIATIONS OF SPECIFIC run the battery (Fig 24-10). GRAVITY WITH TEMPERATURE The electrolyte thickens (gains 24-20 CHARGE INDICATOR ON specific gravity) as it coos. It loses MAINTENANCE FREE BATTERIES specific gravity, as it gets hot. On the Many maintenance free batteries ball hydrometer this is not important. have a charge indicator on their top But on the float hydrometer (Fig 24-11) The appearance of the correction of the specific gravity charge indicator shows the state of reading should be made if the charge of the battery. electrolyte temperature is well above 0 0 CAUTION If the charge indicator or below the 80 F [27 C] standard. shows yellow do not attempt to Specific gravity changes about four 0 recharge or test the battery. It is points for every 10 F change in close to failure and should be temperature. A reading of 1.250 at 0 0 replaced. Never attempt to jump- 120 F (48.9 C ) would correct to start the car if the charge indicator 1.266 (add 0.016 or 4x 0.004) A 0 0 shows yellow (25-9) reading of 1.230 at 20 F (-6.7 C) would correct to 1.206 (subtract 6x 24-21 BATTERY-CAPACITY (HIGH 0.004 or 0.024). DISCHARGE) TEST For this test a special tester is used. 24-17 LOSS OF SPECIFIC It places a load on the battery GRAVITY FROM AGE voltage can be measured while a As a battery ages the electrolyte gradually loses specific gravity. This loss is due to aging and nothing can be done about it. Eventually the

9 Specific gravity Freezing 24-22 BATTERY SERVICE Temperature Battery service can be divided into Degrees F(C) four parts visual inspection testing 1.100 18 [-8.2] charging and care of batteries in 1.100 1[-17.2] stock. 1.200 -17[-27.3] 1.320 -31[-35] 24-23 BATTERY TESTING AND 1.260 -75[-59.4] ANALYSIS 1.300 -95[-70.5] Battery testing includes a check of the condition of the battery. It should Fig 24-10 Specific gravities and also include analysis of any freezing temperatures for battery abnormality found so that corrections electrolyte. can be made. This will prevent a repetition of trouble. Following are various battery troubles and their possible causes. These apply mainly to vent-plug batteries 1. Overcharging -If the battery frequently requires after, it is probably being over being overcharged. Too much current is Fig 24-11 being supplied to the battery. This is Appearance of the charge indicator in the a damaging condition that overworks top of some maintenance-free batteries (A) the active materials in the battery If the green dot shows the battery is charged (B) If the indicator shows black the battery and shortens battery life. In addition low and should be charged before testing overcharging causes more rapid loss (C) If the indicator shows light yellow the of water from the battery electrolyte. battery is dead and should be discarded. Unless this water is replaced High current flowing out of the frequently the electrolyte level is battery. Specifications for this test likely to fall below the tops of the vary. Follow the procedure in the plates. This exposes the plates and tester operating instructions. the separators to the air and may run Specifications for voltage and battery them. Also battery overcharge capacity are in the manufacturer’s causes the battery plates to buckle service manual. In general a load of and crumble. Therefore a battery three times the battery ampere-hour subjected to severe overcharging will capacity is placed on the battery. soon be ruined Where overcharging You can also use one-half of the 0 0 is experienced or suspected the cold-cranking rate at 0 F (- 17.8 C). charging system should be checked. At the end of 15 seconds a good It should be serviced if necessary to battery should show a voltage of 9.6 prevent overcharging (Chap 26). volts or together. If the voltage is 2. Undercharging- If the battery is less than 9.6 volts and the battery discharged, it should be recharged has removable vent plugs check the as outlined later in this chapter. In specific gravity of each cell if there is addition an attempt should be made more than a 50-point difference between cells replace the battery.

10 to determining the cause of the spraying of battery electrolyte is trouble. It could be caused by: natural as the battery is being a. Charging-system malfunctioning. charged. The battery holder may b. Defective connections in the become corroded from the effects of charging circuit between the the electrolyte. Such corrosion may alternator and the battery. be cleaned off, with the battery c. Excessive load demands on the removed. Use a wire brush and a battery. solution of baking soda and water. d. A defective battery. 8.Dirty Battery Top- The top of the e. Permitting the battery to stand battery may become covered with idle for long periods so that it self dirt and grime mixed with electrolyte discharges excessively. sprayed from the battery. This In addition an old battery may have a should be cleaned off periodically low specific-gravity reading because (24.13). it is approaching failure. 9. Discharge to Metallic Hold- 3. Sulfation -The active materials in Down- the plates are converted into active If the hold down clamps are the material during recharge. However if uncovered metallic type, a show the battery stands for long periods in discharge may occur from the a discharged condition the lead insulted terminal to the hold down sulfate is converted into hard clamp. This is more apt to occur with crystalline substance. This a dirty battery top across which substance is difficult to reconvert into current can leak. The remedy to active materials by normal charging keep the battery top clean and dry. processes. Such a battery should be charged at half the normal rate for 60 24-24 REMOVING AND to 100 hours. Even though this long REPLACING BATTERY charging period may convert the To remove a battery from a car first sulfate to active material, the battery take off the grounded battery- may still remain in a damaged terminal cable clamp. This prevents condition. The crystalline sulfate, as accidental grounding of the insulted it forms tends to break the plate terminal when it is disconnected To grids. remove a nut-and-bolt type of cable 4. Cracked Case- A cracked case loosen the clamp out about 3/6 inch may result from excessively loose (9.5 mm) Use a box wrench or tight hold-down champs, from battery special cable pliers. Do not use freezing or from flying stones. ordinary pliers or an open-end 5. Bulged Cases - Bulged cases wrench. Either of these might break result from tight hold-down clamps cell cover when swung ground. If the from high temperatures. clamp sticks, use a clamp puller. Do 6. Corroded Terminals and Cable not use a screwdriver or bar to pry Clamps -The condition occurs on the clamp. This could damage the naturally on batteries. Excessive battery cell all or cover. To detach corrosion should be removed from the spring-ring type of clamp cable clamps and terminals(24-13) squeeze the ends of the rings apart 7. Corroded Battery Holdo- Some with Vise-Grip or Cannel lock pliers.

11 After the grounded cable is charging current. At the same time, disconnected disconnect the the current input gradually tapers off. insulted-terminal cable. Clean both When the battery is fully charged the battery terminals and cable clamps current input has been reduced to a (24.7) Loosen the battery hold- few amperes. The battery electrolyte downs and take out the battery. temperature must remain within When installing a battery do not limits. If the battery electrolyte reverse terminal connections. temperature increases greatly the Reconnect the insulted-terminal resistance of the battery will remain cable Apply corrosion inhibitor to low. Then the battery will be clamps and terminals. Install and damaged by overcharging unless it tighten the hold-downs. Avoid is quickly removed from the charger. overtightening. Before charging battery check the Careful -Make sure the cable clamps electrolyte level If the level is low, the are light and make good connections battery can be damaged. If the level with the terminal posts (top terminal is too high the electrolyte can battery) If the jaws of fine clamp overflow because of gassing and touch together the clamp is not tight heat. Here are cautions to observe. on the post. Shave the clamp jaws 1. The gases released by batteries with a file until there is a gap when under charger are very explosive. the clamp is installed. Be sure the area is well ventilated. Do not smoke on have 24-25 BATTERY ADDITIVES open flames around charging Certain chemical compounds when batteries This could cause an added to the battery cells are explosion supposed to restore a battery to a 2. Be sure to disconnect the battery charged condition. Such chemicals ground step if the battery being should never added the battery. charged in a car Otherwise you Their use may void the battery can damage the electrical guarantee and cause battery failure. equipment in the car 24-26 BATERY SLOW CHARGING 3. Most manufacturers Two methods of slow charging recommended leaving the cell batteries are in use, the constant- caps in place. But make sure the current and the constant-voltage vent holes are open. Cover the methods. In the constant-current caps with a cloth during the method, the current input to the charging procedure Some battery is adjusted to the manufacturers recommended manufacturer’s specifications. The removing the caps and coving the charging is continued until the openings with a cloth battery is gassing freely and there is 4. Do not charge a battery that is no rise in specific gravity for 2 hours. frozen. It could explode In the constant-voltage method, the 5. Always wear some type of eye charging voltage is held at a protection constant value. The battery, as it 6. If the charger indicator of a approaches a charged condition maintenance-free battery shows increases in resistance to the yellow on clear, do not charge it.

12 The electrolyte level is low, and Likewise a badly sullated battery charging it could cause an should not be quick charged. Such explosion. The battery should be batteries may be near failure but discharged they may give additional service if 7. Do not turn the charger on until slow charged However quick the charger cables are connected charging might damage them further. to the battery. Turn the charger During quick charging check the off before disconnecting the color of the electrolyte Stop charging cables if it becomes discolored as a result of 8. Check the specific gravity and the stirring up of washed-out active temperature of the electrolyte plate material Likewise cell voltages periodically during charge. If the should be checked every few temperature goes above 125 0F minutes Charging should be stopped (51.7 0C) stop the charge. it cell voltages vary more than 0.2 9. The battery is fully charged when volt. the specific gravity shows no Careful -When quick charging a increase for 3 hours. Also the battery in a car disconnect the cells should be gassing freely battery ground strap to protect the 10. After charging, wash and dry the electrical system from damage due battery top. This removes any to high voltage. If the charge electrolyte that might have indicator in a maintenance free spewed out during charge. battery shows yellow do not try to quick charge it(24-20) 24-27 QUICK CHARGERS The quick charger can be wheeled up to the car and connected to the battery in the car (Fig 24.12) Here are some special points to watch when using a quick charger. These chargers can supply a fast charge of up to 100 amperes (for some types) Normally you would set the charging rate for about 40 to 50 amperes and charge the battery for about 30 to 45 minutes. This boosts the battery with up to 38 ampere does not go above 24.12 Quick charger connected to a 125 0F (51.7 0C) battery in the car. The grounded Quick charging usually cannot bring battery cable should be the battery to full charge in a short disconnected before charger cables time. To bring it up to full charge, the are connected( Chryster battery should be given a slow Corporation). charge after the quick charge. Careful -A battery with discolored A very low battery may not accept a electrolyte (from cycling) or with fast charge. The electrolyte in a very gravity readings more than 25 points low battery does not have very much apart should not be quick charged. sulfuric acid in it. Therefore, the

13 conductivity of the electrolyte is too 2. Remove the lid from the low to allow a high current to flow electrolyte container. Unfold the through the battery. You might think top of the plastic bag, and cut a a battery that refuses to make a high small opening in one corner of charge is torn out. However, it may the bag be possible to restore the battery to 3. Use a glass acid-proof funnel and a charged condition. First slow fill each battery cell. Wear charge it for a few minutes to see goggles and observe all cautions whether it starts coming up to already noted regaraging sulfuric charge. If does, then it can be put on acid. Wait a few minutes and fast charge. then add more electrolyte if necessary. Some electrolyte will 24-28 CARE OF BATTERIES IN probably be left. Do not attempt STOCK to use it all. Do not overfill the Wet batteries (new batteries shipped battery. with electrolyte in them) their 4. Before discharging the container, perishable. They are subject to self- empty it Rinse the bag thoroughly discharge. If allowed to prevent this with water. Otherwise someone batteries in stock should be who handles the carton might be recharged every 30 days. They severely burned. should not be stacked on top each other without additional support. The weight of one battery is enough to collapse the plate assemblies.

24-29 DRY-CHARGED BATTERIES Dry-charged batteries contain fully charged positive and negative plates but no electrolyte. The batteries are sealed with rubber or plastic seals placed in the vent plugs. Since the batteries contain no moisture practically no chemical action can take place in them. This means that they will remain in good condition for as long as 36 months. Dry-charged battery manufacturers supply ready-mixed electrolyte in special cartons. The carton contains an acid proof plastic bag, which holds the electrolyte. The following steps are performed to activate a dry-charged battery 1. Remove the vent plugs, and take out the plastic seals

14 a. supply current for cranking the engine b. supply current when the charging system can’t handle the complete electrical load c. both of the above d. neither of the above 5. The length of time in minutes that a fully charged battery at 80 0F (26.7 0C) can deliver 25 amperes is called the (24-6) *****REVIEW QUESTIONS******* a. charging rate Select the one correct. best or most b. reserve capacity probable answer to each question. c. Cold-cranking rate You can find the answers in the d. ampere-hour rate section indicated at the end of each 6. The number of amperes that the question. battery can deliver for 30 1.When working around batteries seconds when it is at 0 0F (1- remember that (24-10) 17.8 0C) before the battery voltage a. battery electrolyte contains a very falls to 7.2 volts is called the (24- corrosive acid. 6) b. explosive gas forms in the battery a. charging rate which it is being charged. b. reserve capacity c. the battery can furnish a very high c. cold-cranking rate current if it is shorted. d. ampere-hour rate d. all of the above. 7. If you must add water to the 2. When disconnecting a battery always battery every few days, the (24-10) battery probably (24-23 a. remove the vent plugs first a. overloaded b. disconnect the insulated – b. overcharged terminal cable first c. sulfated c. disconnect the grounded- d. old terminal cable first 8. A loose battery-cable clamp d. put the transmission in PARK could cause (24-23) or REVERSE. a. battery overcharged 3. The battery is an b. high battery voltage electrochemical device. This c. overheating means that the battery(24-1) d. run down battery a. makes chemicals by 9. On a top-terminal battery, the mechanical means negative terminal post is (24-3) b. uses chemical action to provide a. Smaller than the positive electricity. terminal post c. has curved instead of flat plates b. Larger than the positive d. does not use an electrolyte. terminal post 4.The purpose of the battery is to(24-1)

15 c. The same size as the positive terminal post d. None of the above 10. You can quick charge the battery at as much as 50 amperes provided (24-27) a. the electrolyte does not get too hot b. you do not charge for more than 5 minutes c. you make sure the battery is fully charged d. It remains connected to the electrical system.

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