LUKAS LK-530-12V Dash Cam Smart Power Supply Battery Pack (All in one Potable UPS) For Car Blackbox Portable UPS is located between the vehicle Battery and the equipment in use(Black box, Navigation etc.) It must need to activate parking mode in a black box for the secondary power during key off. If DC-power become cut off, it starts to supply secondary power automatically on behalf of vehicle battery until start engine 2H may need for full charge and supply for max 9H Please visit [ http://lukashd.com/eng/product_info/power_lock_3.html ]