It doesn't though. I've tried that, but since charging in NITDroid doesn't work when it is sleeping you have to interact with it every so often to stop it sleeping which makes charging in NITDroid a right royal pain. But still after doing that, it doesn't fix the problem which is NITDroid doesn't (or can't) read the battery's current charge level. What works just as well is putting a 95% charged battery in and let NITDroid charge the final 5% becuase it does at least know when the battery has finished charging and will mark the battery fully charged when it reaches that point, if you have a fully charged battery you may need to discharge it a little before NITDroid will start charging it.