Drive Motor Battery System Description: Notes

WARNING: This page is about a different variant/trim than selected.

Fig 1: Drive Motor Battery System Diagram

Courtesy of GENERAL MOTORS COMPANY

The hybrid energy storage system uses a number of modules and components to store electricity for use by the eAssist system. The hybrid energy storage system stores 115 V DC in two lithium-ion battery sections. Current flows from the battery sections through a series of contactors and a service disconnect. This allows the system to control the disconnect of high voltage from the vehicle and also creates a redundant disconnect to ensure voltage is disabled when servicing high voltage components. To ensure optimum life of the lithium-ion batteries, the hybrid energy storage system monitors the state of charge of each battery cell. The system will equalize the state of charge of each cell through a balancing process. The hybrid energy storage system is also responsible for monitoring and controlling the charging and the discharging of the high voltage battery.

The high voltage battery is charged during normal vehicle driving. During normal operation, the high voltage battery is kept at or near an optimum level of charge. In some case, such as the installation of a replacement high voltage battery, the battery state of charge may be low and require charging before the eAssist system functions begin to operate normally. To charge the battery, drive the vehicle or allow the vehicle to idle with the transmission in Park or Neutral. To decrease charging time, raise the engine speed to 2,500 - 3,000 RPM with the transmission in Neutral. This will increase the charging rate and decrease charging time.

The primary component of the hybrid energy storage system is the Hybrid/EV Battery Pack. The Hybrid/EV Battery Pack is a modular battery pack assembly that not only contains the lithium-ion battery sections, but also many of the control modules and components used by the eAssist system.

The Hybrid/EV Battery Pack contains the following serviceable components:

Hybrid/EV Battery Section 1
Hybrid/EV Battery Section 2
Battery Energy Control Module
Starter/Generator Control Module
Main Contactor - located in the generator battery disconnect relay assembly
Pre-Charge Contactor - located in the generator battery disconnect relay assembly
Hybrid/EV Battery Pre-Charge Resistor - located in the generator battery disconnect relay assembly
Hybrid/EV Battery Pack Current Sensor - located in the generator battery disconnect relay assembly
Hybrid/EV Battery Pack High Voltage Manual Disconnect Lever - located in the battery energy control module wiring junction block assembly
Generator Battery Fuse - located in the battery energy control module wiring junction block assembly
High Voltage Interlock Switch