I picked up one of the refurb iPhones from AT&T, unlocked it, and have been using it for a few weeks with a t-mobile pay as you go plan. It's worked fine, charged quickly ( a few hours ), and the battery-life was several days without a lot of active use, even with wireless on. Two days ago I had it connected through the dock connector to my alpine car stereo. It was playing fine, but at some point I had to restart my car, and the iphone wasn't found by the car stereo. I had to do a hard reset of the iphone, at which point the screen flashed for a while, and then eventually it came back on. Things seemed ok, but the next morning the phone had completely lost its charge from a full charge the day before. It no longer would take a charge from my firewire docks like it had previously, and took a full 24 hours to fully charge via usb. Today I've just watched the charge drain, and it's lost a full half of the battery charge today despite being on standby for the entire day, with wireless turned off. Clearly something's amiss, but do any of you have any ideas of what to do about it? It's been activated previously (as it was a refurb), but I don't have an AT&T plan, so I can't imagine Apple will service it, even if I re-lock it. Is this likely to be just a battery issue, that I can pay to just replace the battery to fix? Any other ideas? Thanks. I'm at a loss. Everything else on the phone seems to work totally fine, just anything to do with the battery seems a bit off.