Circuit/System Description

The A28 Hybrid/Electric Vehicle Battery Disconnect Relay assembly contains all ten high voltage contactors, and two single-use High Voltage cut-off actuators. The high voltage contactors allow the high voltage DC batteries to be connected to the vehicle or contain the high voltage DC within the hybrid/EV battery assembly during normal operation. Additionally, they allow for series configuring the two battery layers for 800V DC charging.

In order to prevent large in-rush current, system bus high voltage is routed through a pre-charge resistor whenever high voltage is commanded ON. The K16 battery energy control module monitors the time it takes the system bus voltage to attain the same level as the battery pack voltage. If it takes too long, a DTC is set.