How big is the percentage for drain? Normally, even when a device is not doing anything, there will be somewhat of a drain regardless. Nothing that really can be done, that is just how electric devices are. With that said, I normally see a 4% drop overnight. Been that way for years though, nothing new. Also, if you use cellular and your signal is less than ideal, the drain will be greater. Been that way since cellphones first became a thing.