How to monitor a car's 12 V battery in Home Assistant with ESP32
My car is a Hyundai Ioniq 5. Like most EVs, it still has an ordinary 12 V battery, and that battery decides whether the car wakes up at all. If it’s flat, a full high-voltage pack doesn’t help: the car won’t go into ready mode. The 12 V battery is charged from the high-voltage pack, so a problem on that side can drain it without warning. I want to know the 12 V voltage every day, not only when the car refuses to start. ...