if the battery is TOTAL draned the battery will show as a bad battery. I recently bought 5 8700 c-s2 batteries off of ebay (they where OEM) 4 of the 5 came up as bad but; after leaving them in the phone and charging for a short time (ten mintues or so) they charged up full fine.
Originally Posted by matrodriguez
If the battery is in then yes that means it's probably a bad battery or you don't have the battery connected properly. Normally that icon comes up when the battery isn't connected whatsoever.
Make sure you have the battery connected correctly, and then try charging the phone. If the problem persists then I suggest purchasing a new battery of the same type.
You could try software updates as well.