I wasn't going to use it while I'm trying to charge it... I mean, I kind of hold phone with my hand covering the back and all
About the external pad thing, I could just buy a solar charger for the phone, those are fairly cheap now too, but I wanted it flush with back of phone so it didn't make it larger. I could always drill extra holes around the back if those little squares are for ventilation, but since tmobile's TP2 doesn't have them, I thought they were for design and not really a function lol. Or for speaker volume :S Again if it is just little holes being an issue, I see no reason why I couldn't place a couple extra little holes into case lol
Edit: If I got time this weekend or next I'll buy a couple of those solar lights and put some together and see if it does provide enough to charge battery. Before I even try to implant them into back cover, I suppose it would be smart to do it with just the solar panels laying out first lol. Have to find a mini usb cord to cut open so I can hook it to solar cells and then into phone