A dashcam will slightly drain your car battery, though the power draw is so low, this is unlikely to be an issue. When your engine is off, most dash cams will enter a low-power mode and only record if an event is detected.
The A139 Pro is compatible with the Viofo HK3-C ACC hardware kit, which is an external battery that prevents the A139 from draining your vehicle’s battery while in continuous recording parking mode.