Viofo EP100 Expansion Battery for BP100 Expand Capacity for Longer Parking ModeVIOFO EP100 Expansion Battery Expansion Battery for BP100 Battery Pack, Easy to Expand Capacity for Much Longer Parking Recording EP100 cannot operate independently and must be used with BP100 Expansion Battery The EP100 expansion battery is designed to easily add the capacity to the BP100 dash cam battery pack. Expand your power up to 22950mAh for much longer parking recording with 1X BP100 and 2x EP100