Anybody who has around 1000 mAh or less according to ibackupbot should take it to their nearest genius bar if possible (even if your warranty has lapsed). It seems to me that there were some bum batteries on the iPhone 5. I had 200 cycles on mine and it was being reported as ~900 mAh at full charge. Apple swapped it out and the genius said his tests showed it was only around 40% of the original capacity.
My phone is under applecare+ but to me this is a defect in the battery and if you are nice to the genius, I bet they will make it right for you.
My phone is under applecare+ but to me this is a defect in the battery and if you are nice to the genius, I bet they will make it right for you.