The generator battery carrier assembly contains several individually serviceable components:

The generator battery carrier assembly contains several individually serviceable components: the generator battery, generator battery vent fan, generator battery temperature sensors, generator battery temperature sensor wiring harness, generator battery fuse/fuse nut, generator battery disconnect control module and the generator battery disconnect control module cover.

A serviceable 36-volt nickel metal hydride battery is located behind the rear seat, beneath the load floor. The battery contains 3 separate 12-volt cassettes which are wired together in series. The cassettes are serviceable and weigh approximately 10 pounds each. The cassettes will not be serviced individually, they will be replaced as a set of 3. Each cassette contains 2 non-serviceable, 12-volt, 8.5 amp-hr modules which are connected in parallel using bus bars.

The generator battery vent fan is a serviceable component attached to the rear of the generator battery carrier assembly. This variable speed fan is controlled and powered by the generator battery disconnect control module. The fan draws cooling air through the bottom of the generator battery carrier assembly, exhausting it to the exterior of the vehicle. Fan speed is varied, as required, to ensure that generator battery temperature remains within desired limits.

Each battery module has a separate temperature sensor, or thermistor. These sensors are serviced as a pair (one pair for each battery cassette). The battery cassette must be removed from the vehicle in order to access the thermistors. These sensors receive power and provide a battery temperature feedback signal to the generator battery disconnect control module through the generator battery temperature sensor wiring harness.

The generator battery temperature sensor wiring harness is a serviceable component contained within the generator battery carrier assembly. It serves as a conduit for the battery temperature and voltage feedback signals which are processed by the generator battery disconnect control module. The harness features individual voltage terminals for each battery cassette as well as separate connectors for each of the 3 generator battery temperature sensor assemblies. The connector on the opposing end of the harness mates with the generator battery disconnect control module.

The vehicles 36-volt electrical system is protected from excessive current by a 200 amp fuse located at the negative terminal of the generator battery. This fuse features an indicator window which should be oriented toward the top of the generator battery. The fuse is applied outboard of the negative 36-volt battery cable and is held in place by a serviceable, non-conductive generator battery fuse nut.

The generator battery disconnect control module, sometimes referred to as the battery disconnect unit (BDU) or battery energy control module (BECM), is a serviceable GMLAN device which is mounted to the rear of the generator battery carrier assembly. This controller also includes several non-serviceable sub-components, including a current sensor, service disconnect switch and the 36-volt system contactor. The generator battery disconnect control module controls the generator battery vent fan and monitors temperature, voltage and current levels within the generator battery. The service disconnect switch attached to the controller is a plunger type switch used to open the 36-volt system contactor during service activities. The switches plunger rests against the generator battery disconnect control module cover, and it closes when the cover is closed and opens when the cover is opened. The 36-volt system contactor will open and close in conjunction with the service disconnect switch. When the contactor is in an open position, the generator battery will be electrically isolated from the vehicle, although intermediate voltage potential will still be present within the generator battery carrier assembly and the generator battery disconnect control module.

The generator battery disconnect control module cover, sometimes referred to as the battery disconnect unit cover (or BDU cover), is a serviceable, hinged panel attached to the rear of the generator battery carrier assembly. This cover shields personnel from intermediate voltage potential when properly secured in a closed position. The service disconnect switch plunger rests against the generator battery disconnect control module cover such that the switch will open with the cover in an open position, and it will close when the cover is in a closed position. The cover is securely fastened to the generator battery carrier assembly by an M6 bolt with a 10 mm hex head.