FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

System Operation

SYSTEM OPERATION
Battery Ignition Off Draw (IOD)
A completely normal vehicle will have a small amount of current drain on the battery with the key out of the ignition. It can range from 4 to 10 milliamperes after all the modules time out. If a vehicle will not be operated for Approx 20 Days, the IOD fuse should be disconnected to minimize the vehicle electrical drain on the battery. The IOD fuse is located in the Power Distribution Center ([1][2]PDC). Refer to the PDC to locate the cover proper fuse.

Charging Time Required

WARNING: NEVER EXCEED 20 AMPS WHEN CHARGING A COLD -1°C (30°F) BATTERY. PERSONAL INJURY MAY RESULT.

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

Battery Charging Time:




Size Of Battery
A completely discharged large heavy-duty battery may require more recharging time than a completely discharged small capacity battery, refer to for charging times.

Temperature
A longer time will be needed to charge a battery at -18 °C (0 °F) than at 27 °C (80 °F). When a fast charger is connected to a cold battery, current accepted by battery will be very low at first. in time, the battery will accept a higher rate as battery temperature warms.

Charger Capacity
A charger which can supply only five Amperes will require a much longer period of charging than a charger that can supply 20 Amperes or more.


Built-In Test Indicator Sight Glass:




State Of Charge
A completely discharged battery requires more charging time than a partially charged battery. Electrolyte is nearly pure water in a completely discharged battery. At first, the charging current Amperage will be low. As water is converted back to sulfuric acid inside the battery, the current Amp rate will rise. Also, the specific gravity of the electrolyte will rise, bringing the green ball into view at approximately 75 percent state-of-charge.