The AEM EV Battery Management System (BMS-18) is comprised of three components: 1. VCU 2.BMS-18 Master 3. BMS-18 Satellite(s) The BMS is implemented as two different Module types: the BMS Master and the BMS Satellite. Each Module is capable of measuring up to 18 cells and 3 temperatures (thermistors) but the Master also contains the CAN communication interface and J1772 charging specific connections needed for each battery pack. The VCU communicates with the BMS via the Master Module and all battery packs need at least one Master unit. The Satellite Modules are connected to their Master via a high-speed serial interface (isoSPI) that allows additional units to be daisy chained together, adding as many Satellites as necessary for the battery pack configuration. The VCU is responsible for all BMS control logic. All setup and calibration items can be modified using the AEMCal user interface.