| | Re: My bb 9900 shutdown totaly no power after charging
If you consistently let the device rundown past 20%, you might have damaged the battery.
You can try removing the battery, placing the device on a wall charger and then insert the battery and see if it will charge. Typically, you need to get past a certain point, around 10-15% charge before the device will turn on. That might take an hour or two.
If that fails, try a new OEM battery made for your specific model.