I have had my dash cam plugged into the cig lighter for months now and don't ever unplug it. I have even forgot to shut the camera off a couple of times and it has run for an entire weekend without the truck even starting. Come Monday morning it starts up every time no problem.

 

I wired my dash cam right to the battery. 2 camera model. Sometimes truck is parked for 2-3 days - never had an issue with the battery.