My wife has an iPhone 6s and in the last 3 days it's been playing up
She charges it every night and in the morning it's charged 100%, but sometimes when she takes it off the charger, the screen goes blank and the apple logo comes on and the phone restarts... then it says she only has 10% battery left. she is constantly charging it and leaves it on charge at work
Does this mean the battery is dying / dead, or could it be another problem?
if anyone has any ideas / advice it would be much appreciated
last thing she wants to do is fork out for a new phone