What is Onboard Charger?

An onboard charger is the component inside an electric vehicle that converts alternating current from a home outlet or Level 2 charger into the direct current the battery stores. Its power rating, measured in kilowatts, sets the maximum speed at which the vehicle can accept AC charging, regardless of how powerful the wall charger is. For example, a vehicle with a smaller onboard charger will charge more slowly on Level 2 even when connected to a higher-capacity unit. This is different from DC fast charging, which bypasses the onboard charger and sends direct current straight to the battery. For dealerships, explaining the onboard charger helps set realistic expectations about home charging times and prevents customers from overspending on a home charger their vehicle cannot fully use. Matching the home charger to the vehicle's onboard charger capacity gives customers the best practical value.