I don't know if anyone else has experienced this or if it's just me, but I wanted to share before someone else made the same mistake. I purchased an extended battery with cover (your normal China brand stuff), which looked good on the page. Photos made it look to be of decent quality, and I made sure to get one that had actual metal for the antenna connections (some are just painted to look like they are there, when they actually aren't). Anyways, I got the battery (which does work pretty well), however cell coverage was horrible and I could rarely get a consistent data connection. Turns out there is an issue between the phone and the antennas on the extended battery case, even though it looks the same they aren't. So for those that buy extended batteries with cases on eBay, just watch out!