This happened after a windows update. It doesn't charge when on or off. I tried uninstalling and reinstalling battery drivers already. I've also tried draining it which made it harder for me since it turns off now whenever the charger is unplugged.
It likely wasn't an update, just bad timing. However, if you feel the update was the problem, you can try going into "System Restore" and find a restore date that is prior to the update. Return the computer to that point and see if it resolves the issue. If it does, then the update was at fault. If it doesn't, then it was just a timing thing and the battery is likely in need of replacing.