What is an onboard charger and how does it work?

The onboard charger (OBC) converts AC power from the grid (Level 1 or Level 2 charging) to DC power for charging the battery. It includes rectification, power factor correction, and DC-DC conversion stages. OBC power levels typically range from 6.6 to 22 kW, determining AC charging speed. DC fast chargers bypass the OBC, charging the battery directly. The OBC must communicate with the charging station for safe, optimized charging.