I am at a complete loss.
The only thing I can possibly think of, is taking the entire thing apart and putting it back together slowly. Sometimes you can find something you missed or did wrong or was damaged.
I've got nothing else :/
This is the battery:
Li-lon 11.1V 2200mAHr Battery Pack, over 2.5hrs Battery Life Universal 19/20, 100-240V, 50W
Just look around for that type and you're set.