I've dealt with a LOT of battery issues. The truck goes to sleep after a few minutes even with doors open. It only goes into deep sleep with the truck locked. When in sleep mode and not locked, it'll try to communicate with the key fob waiting in listening mode. I actually use a faraday key sleeve to block the key fob from communicating while I'm sleeping in the truck or tenting close by with the truck unlocked. I find it unnecessary to lock the truck while camping on BLM with no one around me for miles away.