Auxiliary Battery - Description

DESCRIPTION

WARNING: The auxiliary battery should only be charged and tested with the OTC One Step Battery Analyzer and Charger or equivalent. Never test the auxiliary battery with a Midtronics Micro 420 battery tester.

WARNING: Never jump start the vehicle with the auxiliary battery. Vehicle jump starting should only be performed at the remote battery terminals in the engine compartment or at the starter battery itself.

The auxiliary battery is located in the left side of the engine compartment. The battery is a Semi-Traction battery designed to provide small amounts of current over a long time period, and is not designed for high currents. The auxiliary battery is used to power optional equipment such as trailers, lift gates, refrigeration units, and service and emergency vehicles.

A auxiliary battery cutoff relay is used to prevent discharging the starting battery while operating optional equipment. The relay is located in the driver seat riser. The relay coil is grounded to the vehicle chassis on one side and receives power from the Body Control Module (BCM) on the other. The battery terminal of the relay is connected to fuse four in the fuse/relay block #1. When the engine is running the BCM powers the coil and energizes the auxiliary battery relay. This connects the auxiliary battery to the vehicle battery.

The battery is used to store electrical energy potential in a chemical form. When an electrical load is applied to the battery terminals, an electrochemical reaction occurs within the battery. This reaction causes the battery to discharge electrical current.