Circuit/System Description

The hybrid battery pack contains a total of 32 cell groups in the hybrid/EV battery pack assembly. These cell groups are electrically connected in series. Each individual cell group is rated at 3.7 V, for a nominal system voltage of 118 V DC. The battery cells are grouped together into two sections, each with 16 cell groups.

The battery energy control module monitors the voltage of the 32 battery cell groups. A voltage sense circuit is attached to each individual cell group. Each of these circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connectors the voltage sense circuits to the battery energy control module, located directly above the hybrid battery pack.

To ensure proper battery function and lengthen battery life, the battery energy control processor balances the voltage of the cells so that each cells maintains the same voltage level. The battery energy control module uses internal voltage gates to transfer voltage from cells with a higher voltage level to those cells with a lower voltage level. This voltage balancing is an internal function to the battery energy control module.

The cell voltages are read through multiplexer circuits which take the voltages from multiple battery cells and supplies them to one single analog to digital converter. To determine if the multiplexer is operating correctly, the balancing gates are operated by the battery energy control module one at a time, shifting each cell voltage while the balance gate is on. This cell voltage pattern is analyzed by the starter/generator control module to determine if there is a cell voltage multiplexer malfunction.