Hey! going to try keep this short and sweet since i just typed out loads and my browser decided to log me out! lol! right so here it is: yesterday 11:20am. got a replacement iphone 3gs. came home sync'd and fully charged phone. used as normal for texting/surfing wifi/gprs. 1/4 brightness. no 3g, location services or push. battery indicator went down a little but after another few hours of using i noticed it wasnt going down so checked percentage and it had only moved 1% I was so happy with excellent battery performance. Went to use phone later but the phone had turned off! why would it turn off with about 3/4 full battery? Okay so when i went to sleep i had bout 50-60% battery. on standby all night. woke up with bout 40-50% battery. decided to plug in phone for 20-30 minutes for extra juice. battery goes red and down to 16%! WHY!? a few hours later of usage, was still at 16% so turned phone off a few minutes. was up at 56% great i thought! now that was 4-5 hours ago and im at 42% battery. since yesterdays full charge after getting the phone ive had 4 hours 20 minutes of usage and 22hours 40 minutes standby. but i've had it plugged in 20-30 minutes this morning aswell. should i just calibrate my battery to stop it gettingconfused or take it back? cause it certainly shouldnt be turning off at 3/4 full battery and showing 16% battery when i unplugged from charging the phone up from 40 or so %. please reply!