Porsche 914 Upgrade Project - 23 - The EVTV Tesla Battery Controller

[@zuccamachine]

Since the ESP has to be on during charging to monitor the cells, the contactors are closed. How are you disabling power to the controller/motor while charging? Another contactor downstream from the ESP output controlled by the keyswitch? And where is the 12V supply for the ESP coming from while the key is off? Draining from the 12V battery while the DCDC is off?

[@MikesTropicalTech]

Good questions! The ESP32 is fed unswitched +12 volts, but there's a separate on/off switch for it so no contactors are engaged and little drain when the car is sitting idle for an extended period. When powered up it draws only about 20 ma. I'm using the J1172 protocol in the AVC2 board to disable the motor controller while charging, along with the key and potbox relays. My use case for the car is looking cool, driving around Barcelona at low speed on nice sunny days. :^) I don't work so there's no commute and I either walk or use the fantastic metro system most of the time to get around. So the car will get very limited time on the road, mostly parked in my space in the basement while fully shut down or charging as needed.