An access system for a vehicle energy storage device includes a housing and an access port in the housing configured for operative communication with the energy storage device. An access door is operatively connected to the housing and is movable between a closed position in which the access door closes the housing, and an open position in which the access door opens the housing. The access door prevents access to the access port in the closed position and permits access to the access port in the open position. A magnet is operatively connected to one of the housing and the access door. A magnetic sensor is operatively connected to the other one of the housing and the access door and detects the proximity of the magnet relative to the sensor. The sensor is operable to provide a signal indicative of whether the access door is in the closed position.