Brought my iPhone 3GS in yesterday for a new battery because the charge wasn't lasting very long. Got it replaced for $35 (after coupon), however I was told to let the new battery die out all the way before fully charging it again in order to make it last the longest. Unfortunately, once it died, I was unable to charge it at all. I went in the next day for another battery replacement, waited an hour or so, and was told that the new battery wasn't taking and that the charging port had to be replaced as well. I was dreading another $50 "upcharge" (no pun intended) for this extra service, but he replaced it for me for free. That's a good guy.