What is a high-voltage battery?

The high-voltage battery, also known as the traction battery, is the large battery pack that powers the car. It operates at several hundred volts, usually 400 or 800. This is different from the small 12-volt battery that powers the on-board electronics. Working on a high-voltage system requires specific knowledge and safety measures. Reading out data via the diagnostic port is safe and does not touch the system itself.