Chevrolet Equinox Service Manual: Battery Charging Low Voltage Battery

Special Tools

EL 50313 Battery Tester

For equivalent regional tools, refer toSpecial Tools.

Diagnostic AidsFor best results, use an automatic taper-rate battery charger with a voltage capabilityof 16 V.The charging area should be well ventilated.Do not charge a battery that appears to be frozen. Allow the battery to warm to roomtemperature and test it using the EL 50313 before charging.Battery State of Charge

Note:Using voltage to determine the batteries state of charge is only accurate after thebattery has been at rest for 24 hours. This is enough time for the acid in each cellto equalize. If the battery has been charged or discharged in the past 24-hours, thebattery state of charge will only be an estimate.

The maintenance-free batteries state of charge is estimated by reading the voltageof the battery across the battery terminals. Because the voltage is affected by currentflow into or out of the battery, the engine must be stopped and all electrical loadsturned OFF, including parasitic loads, when checking the voltage. The voltage canalso be affected if the battery has just been charged or discharged, so it is importantto considerwhat has happened to the battery in the time just before testing. Use the followingprocedure to determine the battery's state of charge:

Be sure all electrical loads are turned OFF.Determine whether the battery has been used in a vehicle or charged within the past12 hours.If the answer is no, the terminal voltage will be stabilized and no action is necessarybefore reading the voltage. Skip to step 3.If the answer is yes, terminal voltage will not be stabilized and you should wait12 hours since the last time the battery was used.Estimate the battery temperature by determining the average temperature to which thebattery has been exposed for the past 12 hours.

Note:The table is accurate to 10 % only after the battery has been at rest for 12 hours.

Measure the battery voltage at the battery terminals. Refer to the following tableto determine the state of charge according to the estimated battery temperature:

Battery Voltage

% Charge at 0°C (32°F)

% Charge at 25°C (75°F)

12.75 V	100%	100%
12.7 V	100%	90%
12.6 V	90%	75%
12.45 V	75%	65%
12.2 V	65%	45%
12.0 V	40%	20%

Use the state of charge information as follows:

A battery with a state of charge that is below 65% must always be recharged beforereturning it to service or continuing storage.A battery with a state of charge that is 65% or greater is generally considered tobe charged enough in order to be returned to normal service or in order to continuestorage. However, if the battery is being used in slow traffic or with short drivetimes, or if the temperature is very hot or very cold, the battery should be fullycharged, to at least 90%, before returning it to service or continuing storage.Charging Time Required

The time required to charge a battery will vary depending upon the following factors:

The battery charger capacity—The higher the charger amperage, the less time it willtake to charge the battery.The state of charge of the battery—A completely discharged battery requires more thantwice as much charging time as a half charged battery. In a discharged battery witha voltage below 11 V, the battery has a very high internal resistance and may onlyaccept a very low current at first. Later, as the charging current causes the acidcontent to increase in the electrolyte, the charging current will increase. Extremelydischargedbatteries may not activate the reversed voltage protection in some chargers. Referto the manufacturer's instructions for operating this circuitry.The temperature of the battery—The colder the battery is, the more time it takes torecharge the battery. The charging current accepted by a cold battery is very lowat first. As the battery warms, the charging current will increase.Charging Procedure

Caution:Turn OFF the ignition when connecting or disconnecting thebattery cables, the battery charger or the jumper cables. Failureto do so may damage the ECM/PCM or other electroniccomponents.

Caution:Refer toFastener Caution.

When charging side-terminal batteries with the battery cables connected, connect thecharger to the positive cable bolt and to a ground located away from the battery.When charging side-terminal batteries with the battery cables disconnected, installthe battery side terminal adapters and connect the charger to the adapters.

Tighten

Tighten the battery side terminal adapters to 15 Y (11 lb ft).

Use the following procedure to charge the battery:

Turn OFF the charger.Ensure that all of the battery terminal connections are clean and tight.Connect the charger positive lead to the battery positive terminal on the batteryor the remote jumper stud underhood.

Caution:Do not connect the negative charger lead to the housings ofother vehicle electrical accessories or equipment. The action ofthe battery charger may damage such equipment.

Connect the negative charger lead to a solid engine ground or to a ground stud inthe engine compartment that is connected directly to the battery negative terminal,but away from the battery. If the negative battery cable is disconnected and a terminaladapter is being used, connect directly to the adapter.Turn ON the charger and set to the highest setting for normal charging.Inspect the battery every half hour after starting the battery charger.Charge the battery until the taper-rate charger indicates that the battery is fullycharged.Estimate the battery temperature by feeling the side of the battery. If it feels hotto the touch or its temperature is over 45°C (125°F), discontinue charging and allowthe battery to cool before resuming charging.After charging, test the battery. Refer toBattery Inspection/Test.