Battery: Description and Operation

INTRODUCTION
The battery stores, stabilizes, and delivers electrical current to operate various electrical systems in the vehicle. The determination of whether a battery is good or bad is made by its ability to accept a charge It also must supply high-amperage current for a long enough period to be able to start the vehicle. The capability of the battery to store electrical current comes from a chemical reaction. This reaction takes place between the sulfuric acid solution (electrolyte) and the lead +/- plates in each cell of the battery. As the battery discharges, the plates react with the acid from the electrolyte. When the charging system charges the battery, the water is converted to sulfuric acid in the battery. The concentration of acid in the electrolyte is measured as specific gravity using a hydrometer. The specific gravity indicates the battery's state-of-charge. The OE battery is sealed and water cannot be added.

The battery is vented to release gases that are created when the battery is being charged and discharged.

The battery must be completely charged, and the battery side, posts, and cable terminals must be cleaned before diagnostic procedures are performed.

SYSTEM OPERATION
Battery Blanket Heater
The blanket heater is used with Alaska and Canada cold weather packages. The 110 volt A.C. blanket heater is used to improve the battery cold start ability. This vehicle has an electronic voltage regulator which controls battery charging. ONLY CHRYSLER approved battery blanket/block heater combination should be used. It is designed to provide optimum charging system performance in very cold ambient temperatures below -17.8° C (0° F). The addition of an aftermarket battery heater or engine block heater will adversely affect battery charging and will result in battery discharge or damage.

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 15 to 30 milliamperes after all the modules time out. If a vehicle will not be operated for approximately a 20 days, the IOD fuse should be disconnected to eliminate the vehicle electrical drain on the battery. The IOD fuse is located in the Junction Block number 5. Removing this fuse will help prevent the battery from discharging during storage.

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.

Size of Battery

Battery Charging Timetable:

A completely discharged large heavy-duty battery may require more recharging time than a completely discharged small capacity battery, refer to Battery Charging Timetable 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.

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. Refer to Battery Charging procedures.