Help with dash cam installation

So im looking to install a dashcam with hardwire to my BYD Seal U Dmi, and I want to be able to record for as long as possible while I’m parked. So i was wondering at what voltage should i make the dash cam turn off so it doesn’t drain my 12v battery And i think also saw someone saying that the 12v battery charges up with the blade battery when it’s low. Is that true? And is is enough to power a dashcam?? (Edit: im interested on the viofo a329s with 3channels)