It's going to be impossible to get everything you want in one camera. Firstly, there are no dash cams that offer a 12-hour battery life because none of them have a large enough battery. We suggest getting one of the dash cams recommend below and an external battery pack — like the ones that can charge up phones on the go. A battery pack mean you'd have to charge the battery pack at your house every day or every few days, then plug it into your dash cam in your car — which is a faff. But leaving a dash cam plugged in constantly will just run your car's battery dead.

As for the dash cam, I would get the Nextbase 512GW and 512GW rear cam (hardwired at Halfords) because it records great quality footage — 1440p @ 30fps (but 1080p @ 60fps is better because the 60 frames per second make the video smoother). While in stand-by mode the camera draws a miniscule amount of power from its internal battery, 1.2mA (0.0012A). The camera’s internal battery could sustain this standby mode for days. If it detects a movement on the forward, backwards, or left and right axis, it'll start recording. You can read the review, and see sample footage of the 512GW here (the rear camera review will go up in the coming weeks): kit.honestjohn.co.uk/reviews/review-nextbase-512gw.../