Usualy is good to have at least 50% battery. Did you tried to charge it trough the wall charger ? Can you enter in download mode ? From fully shutted down , hold vlume up while plugging it to the computer. It should start by displaying Download mode logo. If you get to this point then the device is not bricked, and from here you should be able to reinstall the original 4.2.2(in my case is D80210A_00.kdz, because i have the 802 variant ).