I designed the PCB to eliminate wires within the accumulator and provide a reliable, clean interface for both internal and external electrical components. As space within the accumulator is tight, the board needed to densely mount all the necessary electronics. Within the enclosure, the PCB interfaces with the battery management system, isolation monitoring device, current sensor, motor controller, accumulator isolation relays, CAN network and cooling fans. The internal circuits on the PCB include high voltage (HV) precharge and discharge circuits, an HV DC-DC converter, relay safety circuitry and LED indicators. The precharge circuit charges the capacitors in the motor controller safely. The discharge circuit dissipates the electric energy stored in the capacitors when the car shuts off. Although these circuits are relatively simple, the implementation was challenging due to the high voltage and large amount of power dissipation. To verify that the circuits met the specified time constants, I developed a MATLAB circuit simulation. The layout of the 300V section of the board required extra consideration because of possible arcing.  The PCB also includes connectors to external components which include the car’s LV system, programing ports for the motor controller and BMS, charger and HV tractive system measuring points.