This used to happen to me as well. My solution could work for you.
I dont use the standard stock battery, i bought a double cap booster battery from Ebay. it's twice the size of a standard and comes with it's own cover to support the obesity. once in a while it'll randomly shut off.
my solution is to lay a piece of fold paper on top of the battery, put the cover on and tape the cover down.
obviously the paper provides a thickness so any unexpected motions wont dislodge the battery and the tape holds the cover down as well as makes it harder for the cover to come off.
This works for me |