What creep138 said. The stock charger is rated at 2 amps. If you use like a phone charger that is rated at 1 amp then you are severely extending your charging time. Make sure the charger is OEM Stock (or one rated at 2 amps) and make sure the cable is the thicker cable that came with the Tab.
I can get 100% in a couple of hours after a good hard use. But if I run it over night on the charger, I most definitely get 100% in the morning.