Battery Energy Control Module
The battery energy control module is located directly above the hybrid/EV battery section 1 and hybrid/EV battery section 2. The module is responsible for monitoring the hybrid/EV battery section 1 and hybrid/EV battery section 2 parameters and reporting this to the starter/generator control module. The battery energy control module may also be known as the BECM, voltage current temperature module, or voltage temperature interface module (VTIM).
The battery energy control module monitors the voltage of each battery cell section. 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 connects the voltage sense circuits to the battery energy control module, located directly above the battery sections. The sensor itself is a part of the battery cell and is not serviceable.
The battery energy control module also measures critical temperatures within the two battery sections and at the hybrid/EV battery section 1 air inlet. Six temperature sensors are used to monitor the battery temperature. The battery temperature sensors are located in the battery sections. Two of the temperature sensors are located on the top of the battery section and the remaining four are located on the bottom of the section. The temperature sensor is a variable resistor that measures the temperature of the battery cell group. The battery energy control module supplies 5 V to the signal circuit and a ground for the low reference circuit. The battery temperature sensor resistance changes with battery temperature. As the temperature decreases, the sensor resistance increases. As the temperature increases, the sensor resistance decreases. The air inlet temperature sensor operates in much the same way, except that it measures the temperature of the incoming air used to cool the hybrid/EV battery pack at the hybrid/EV battery section 1 air inlet. None of the temperature sensors or the temperature sensor harness is serviceable. They are all serviced as part of the battery sections.
The battery energy control module is responsible for the cell balancing process. During operation, individual cells may charge or discharge at different rates. To ensure proper battery health and optimal life, these voltages are balanced, with energy from a higher voltage cell being transferred to a lower voltage cell. This keeps the voltage consistent between all 32 cell groups. Cell balancing is an internal process of the battery energy control module. Internal gates allow energy to flow between cells using the same circuits that are used to monitor cell voltage.