It may be the connector on either the phone or charfer and not the battery, the little adapter connector often gets damaged - items get thrown on it, sometimes it can get walked on or fall - that little connecting bit into the phone could be the problem, I have had it a few times and either used a new charger or had to get a new phone, tablet because it, definitely sounds like this if it happened all of a sudden, I use to try jiggle it, place it strategically on a surface but in the end, I had to get upgrades