A system and a method of powering an external device with a vehicular battery system allow a user to charge electrically-powered devices with the electrical power source of his or her vehicle. The system includes an electrically-driven vehicle which includes a high-voltage battery. The system further includes a power modifier, an auxiliary battery, at least one external device, at least one on/off relay, and a user controller. The power modifier modifies the high-voltage DC drawn from the high-voltage battery to safely charge the auxiliary battery. The auxiliary battery stores electrical power. The external device may be any electrically-powered device. The on/off relay allows a user to turn the system on or off when desired. The user controller is communicably coupled to the on/off relay through a relay wireless communication module. The user controller allows a user to remotely operate the on/off relay and, thus, remotely turn the system on or off.