Ok so I bought a new Power Cover for my Surface Pro 2 from eBay. I was using it for about 2-3 weeks while plugged in and everything was working great. Until I unplugged it to use it while on the road. Since I'd just unplugged it, both batteries should have read at 100% but when I turned it on about 10 min after I unplugged it the batter meter read 50%. When I looked the power cover was reading 0%. When I got home and plugged the surface, suddenly the power cover now read 100%. When unplugged it again after fulling charging it, it was the internal battery that was starting to drain, not the power cover. I left it unplugged till the surface almost died and never detached the keyboard. It still read 100% the entire time. Then I put the surface to sleep and when I wake it up 1 min later the power cover then read 0%. I plugged in the charger and the power cover still read 0% after several hours. Then I put it to sleep again, then wake it again after 1 min and the power cover was now 100%. Any thoughts or ideas as to what is happening???