The onboard charger in an EV is responsible for converting alternating current (AC) from a charging station into direct current (DC) that can be stored in the battery. The capacity of the onboard charger determines how quickly the vehicle can charge from an AC source, such as a Level 1 or Level 2 charger. For example, an onboard charger rated at 7.2 kW can add about 25 miles of range per hour of charging. However, when using DC fast chargers, the onboard charger is bypassed, allowing for much faster charging.
