Car Battery
Serviceable dry-charged batteries
-must be filled with electrolyte and charged before installation. The rate of charge is determined by the amp rating of the battery CHARGING RATES THAT EXCEED 15 VOLTS DAMAGE THE BATTERY. ON A SEALED BATTERY, THE MAX CHARGE RATE IS 40 AMPS. NEVER CHARGE A FROZEN BATTERY
Slow charging
-slow charging with a low current is required to completely charge a battery -the maximum charging current should be less than 1/10 of the battery capacity. A 40 AH battery should be charged at 4 amps or less -set the charger switch to the slow position -readjust the current control switch a few times during charging -as the battery becomes fully charged, hydrogen gas is emitted. When there is no further rise in battery voltage for more than one hour, the battery is completely charged.
Installing a battery
#The replacement battery should have ratings equal to manufacturer recommendations. An undersized battery affects starting motor performance and battery life 1-gently place the battery into the clean tray or box 2-make sure the battery fits properly. The tray edge should not cut or rupture the battery case 3-bolt on the battery hold down 4-instal the ground cables
How to properly read the Hydrometer Thermometer
1-Read the hydrometers thermometer and compensate for error with the provided scale 2-compare the reading to the proper specifications. If the specific gravity of the electrolyte in any or all cells falls below 1.225, the battery has a 75% charge. The battery cannot undergo further testing until the battery is charged 3-if the specific gravity of any two cells differs by more than .025, then the battery is considered faulty and must be replaced
Three Types of Battery Ratings
1-The amp-hour (AH) rating is the amount of current a battery produces over a 20hr period at 80 degrees without the terminal voltage falling below 10.5 volts #Most manufactures use an amp per hour rating of 50 to 120 A/H 2-The cold-cranking ampere (CCA) rating is the ability of the battery to provide an amperage load for 30 seconds at zero degrees without the terminal voltage falling below 7.2 volts. Most origional equipment batteries range from 300 CCA to more than 1000 CCA 3-The Reserve Capacity (RC) rating is the amount of time in minutes a battery can be discharged at 25 amps after a charging system failure while at 80 degrees without falling below a battery voltage of 10.5
Types of battery terminals and their locations
1-Top-post terminals are arranged side by side or diagonally. Whereas the side-by-side terminal arrangement has no special designation, the diagonal has an F after their group number 2-In batteries with side post terminals, bolts secure cables to terminals that are molded into the side of the battery case
How to preform an Open Circuit Voltage Test
1-a recently charged battery has a significant surface charge that must be removed before an open-circuit voltage test is preformed 2-a carbon pile or volts-amp tester will place a 20 amp drain on the battery for one minute 3-immediately following the drain, measure the voltage 4-a fully charged battery tests at 12.6 volts. Each .2 volt drop from the 12.6 indicates a 25% decrease in the battery's state-of-charge 5-Any battery below 75% charge should be recharged before any other testing
Equipment Required for the Load Test
1-a voltmeter measures battery voltage 2-an ammeter measures the amount of charge removed from the battery #The ammeter must have a 500 amp range 3-a carbon pile produces a variable load #A battery-starter or volts-amp may be substituted for the equiptment
Equipment required for an open circuit voltage test
1-a voltmeter measures voltage 2-an ammeter measures the amount of charge removed from the battery 3-a carbon pile produces a variable load #A battery-starter or volts-amp tester can be substituted for the equipment
Battery Capacity
1-an engine requires approximately 1 amp of current for each cubic inch of displacement 2-when selecting a battery, make sure the minimum CCA is equal to the cubic inch displacement 3-low temperatures increase the need for engine cranking power while decreasing battery power 4-match the battery voltage to the vehicle. This is usually 12 volts 5-it is not necessary to match the RC rating to the RC rating of the original battery
How to preform a Load Test
1-attach a carbon pile lead, or volts-amp test leads, to the positive or negative terminals of the battery. The load test knob should be turned off 2-clamp the volts-amp tester 40 around the negative cable of the tester 3-attach the voltmeter leads in parallel to to battery 4-create a load on the battery by twisting the carbon pile control knob. Try to maintain the amp flow at load test specifications for 15 seconds #If using individual pieces of test equipment, attach the ammeter leads in series to the carbon pile and the battery. Connect the other leads to the positive or negative terminals of the battery.
How to preform a quick charge test
1-connect the battery charger and voltmeter to the battery. Observe battery polarity 2-set the battery charger to the correct voltage 3-charge the battery at the rate of 40-amps. Do not exceed 40-amps 4-check the voltmeter reading 5-time the process for 3 minutes. Determine the battery's condition with the battery charger still operating 6-The battery is in good condition if the voltmeter reading remains below 15.5 volts
Removing a battery
1-disconnect the cables REMOVE GROUND CABLE FIRST 2-loosen the battery hold-down 3-using a battery strap or tool, lift the battery out of the vehicle
Jump-starting a vehicle
1-inspect the dead battery for cracks and excessive corrosion. Clean the cables before proceeding 2-connect the jumper cables 3-start the donor vehicles engine and let it run for one to two minutes at high idle crank the dead vehicle for 15 seconds then let it rest for 30 4-repeat step 3 until it starts
Using the Battery Charger
1-make sure that the main switch and timer switch are off and the current adjust switch is at the minimum position 2-hook up the positive and negative cables 3-connect the power cable to the electrical outlet 4-set the voltage switch to the correct battery voltage 5-set the main switch at on 6-set the timer to desired time and adjust the charging current to the predetermined amperage 7-when timer goes off, check the charged condition using a voltmeter
How to preform a Preliminary battery load test
1-preform a hydrometer test or an open-circuit voltage test to establish the battery's state-of-charge 2-determine either the amp hours or cold cranking amps to establish the battery's capacity requirements #either the amp hours or cold cranking amps should be noted on the battery's ID tag 3-compare the battery's cold cranking amps to the cubic inch displacement of the engine. In gasoline engines the cold cranking amps should be at least 1 amp per cubic in of displacement #Vehicles with 4 & 6 cylinder engines can require more cranking current per cubic inch of displacement 4-if the cold cranking amp rating is too low, test the battery according to the cold cranking amps rating found on the battery. If the cold-cranking amps are higher than the cubic inch displacement, test the battery according to the cubic inch displacement 5-establish the proper load test specifications. A 12 volt battery should deliver the specified amount of current for 15 seconds without falling below 9.6 volts #A 6-volt battery should never fall below 4.8-volts
How do you preform the hydrometer test?
1-remove the battery cell vent caps. Make sure the cells contain a sufficient amount of electrolyte 2-draw an electrolyte sample from cell 1. Draw enough electrolyte to make the calibrated scale float but not enough to fill the hydrometer 3-hold the hydrometer vertically and read the number that is level with the electrolyte surface 4-record the reading and return the electrolyte sample to cell one
Using a low range ammeter, check for battery drain
1-set the ammeter to the lowest range 2-turn off as many of the circuits as possible 3-disconnect the negative battery terminal 4-connect the negative lead to the negative battery post 5-connect the positive lead to the negative battery terminal/cable 6-Measure the current flow. It should be less than .5 amps. If it is greater than .5 amps, locate the source of the drain and recommend repairs
Equipment needed for the Quick Charge Test
1-the battery charger produces a 40-amp charging rate for three minutes 2-the voltmeter measures an increase in battery voltage during charging 3-a volts-amp tester repeats the load test after a quick charge
Safety Cautions to Jump Starting a Vehicle
1-when exposed to an arc, batter outgassing can cause an explosion 2-Do not attempt to jump start a car with a frozen battery. The rapid expansion of the grid by the donor vehicle can split the frozen battery 3-Jumping a dead battery can cause a current surge that can damage delicate electronic components. Run the donor vehicle while jump starting to regulate the voltage and current surging
Surface Charge
A charge contained on the surface of the battery grids that is not indicative of the battery's true state-of-charge and can provide an erroneous voltage reading
Quick Charge Test, or 3 Minute Charge Test
A test preformed on serviceable batteries that have failed the load test. It measures sulfation within a battery and the battery's ability to recover charge
Battery Starter tester, or Volts-Amp Tester
A tester that combines volt-amp gauges, carbon pile, and sufficient leads to conduct starter, charging, and battery system tests
The Quick Charge Test
DO NOT PREFORM A QUICK CHARGE TEST ON ANY TYPE OF SEALED BATTERY A battery is bad or inadequately charged if it registers below 9.6 volts during the load test. The quick charge test is only for batteries that have failed the load tests
Low Maintenance Batteries
Equipped with cell covers or caps for adding water to the cells. They require water less frequently than conventional batteries
The Hydrometer Test
HYDROMETERS ARE USED TO PREFORM STATE-OF-CHARGE TESTS ON SERVICEABLE BATTERIES 1-The Hydrometer measures the density of electrolyte within a battery. The hydrometer then compares the density of the electrolyte to water #water has a density of 1 2-when the battery is charged, its ability to produce current by way of chemical reaction is restored 3-the hydrometer has a glass float that is calibrated in thousandth of an inch 4-by sampling the acid from each cell, a comparison can be made between the density of the cells being tested and the density of cells from another battery that is known to be at full charge 5-hydrometers must be temperature compensated because the temperature of the electrolyte directly affects its density and specific gravity 6-a fully charged battery has electrolytes with a specific gravity of approximately 1.280. As the battery discharges, the specific gravity of the electrolyte drops
The Surface Leakage Test
MEASURE THE AMOUNT OF CURRENT LEAKAGE BETWEEN THE BATTERY POSTS 1- set the voltmeter to the 16-volt scale 2-connect the negative lead of the voltmeter to the negative battery post 3-move the positive lead of the voltmeter between the posts on the battery #If the reading is above .5 volts, the battery should be cleaned
Procedures for charging a battery
SLOW CHARGING IS PREFERRED 1-clean off the dirt, dust, or corrosion off the battery 2-clean the terminals 3-check the electrolyte level 4-if the battery is charged while on the vehicle, disconnect the negative and positive charging cables
Nonserviceable Batteries
The charging voltage should be limited to a maximum of 15 volts. A state-of-charge indicator is found on some nonserviceable batteries. The indicator is green when charged above 65% and dark when charged below 65%. If the charge indicator is clear, the battery is low on electrolyte and should be replaced
What indicates its Specific Gravity?
The density of the electrolytes. The higher the float rises, the greater the density of the electrolyte
The Load Test
The load test determines the ability of the battery to deliver high current during peak demands. The battery's current delivery is measured against decreasing voltage and compared to the required capacity
The Open Circuit Voltage Test
The solution within a non-serviceable battery is inaccessible and cannot be tested with a hydrometer. Instead a battery's voltage level is related to its state-of-charge
How to preform a battery drain, or parasitic load test
USING A 12-VOLT TEST LIGHT, CHECK FOR A LARGE CURRENT DRAIN ON THE BATTERY 1-set the test light to the lowest range 2-turn off as many of the circuits as possible 3-connect the test light clamp to the negative battery cable 4-connect the test light probe to the negative battery terminal 5-look for a bright light. The parasitic load needs to be repaired if there is a bright light. If the light is dim, proceed to second step
Hydrogen Gas
a by-product of the chemical charging of a battery. Its highly explosive
Battery
a chemical device that produces electricity
Lead Dioxide (PbO2)
a combination of lead and oxygen, also called lead peroxide
Hydrometer
a device for testing the specific gravity of a liquid based on the liquid's density that determines state-of-charge in a battery
Carbon Pile Tester
a device that produces a variable load on a battery
Element
a group of negative and positive plates that are arranged so at full charge they can deliver 2.2 volts
Sulfuric Acid (H2SO4)
a liquid acid that forms electrolyte when mixed with water
Lead (Pb)
a malleable metal that is a useful conductor
Specific Gravity
a measure of the density of a liquid compared to the density of water that is measured by a hydrometer and used to determine a battery's state-of-charge
Electrolyte or Battery Acid
a mixture of sulfuric acid and water that produces a chemical action within the battery
Drain Test, or Parasitic Load Test
a test in which an ammeter is used to measure the amount of current that drains from the battery when all electrical load devices are de-energized
Open-Circuit Voltage Test
a test used primarily on nonserviceable batteries that determines the battery's state-of-charge by measuring battery voltage minus surface charge
Load Test or Capacity Test
a test used to determine the battery's ability to supply a specific amount of amperes based upon it's original ampere hours or cold-cranking amperes capicity
Ampere Hour
a unit of measure for battery capacity
Maintenance Free Battery
batteries that are sealed and do not require additional water
Electrode
the conductor in a cell
Discharge
the flow of electrons from a source
Capacity
the quantity of electrons that can be delivered by an electrical system or electrical device. Its related to time multiplied by ampere hour
Ambient Temperature
the temperate of the air surrounding an object that is measured with either a Celsius or Fahrenheit thermometer