LG G2 "Solved it" low temperature unable to charge battery
I too had the same problems as you, also after i received the Phone back after fixing an broken screen.
The Phone says it's charging, but it isn't.
I noticed a very very thin gab on the left top of the back cover.
I opened the Phone, and saw that the top cover (where the power buttun is) wasn't at his precise place.
It really was a fraction of a millimeter, but still.
I unscrewed it and noticed that there is a very very thin line for the corners, so to get it good on his place you have to first put in the corners of the plate then lower it before screwing it back tight.
Now my back cover closed correctly everywhere.
I put in the charger and voilla, it charged again like it should..
i hope this can help you people somehow.