Onboard Charger (OBC)

An onboard charger (OBC) is the equipment inside an EV that converts AC electricity from a charging point into DC electricity for the high-voltage battery.

Why its rating matters

During AC charging, usable power is limited by the vehicle's OBC, the charging equipment, and the electrical supply. A higher-rated wallbox cannot make a vehicle exceed its onboard AC limit, while a capable OBC may still charge more slowly on a lower-power circuit.

DC fast charging follows a different path: the external charger performs the AC-to-DC conversion and supplies controlled DC to the vehicle, so the OBC's AC rating is not the governing limit for that session.

Some vehicles support single-phase or three-phase AC differently depending on market and configuration. Connector type also does not reveal the OBC rating. See Home Charging for supply phases, charging power, cables, and installation considerations.