I just happen to have come across this earlier today:
Thanks for the input! Isn't it weird of how a software update not even including Siri can effect her?
Offline, as in not connected to the Internet? I'm sure it's normal, as long as the battery depletion is not too much. The phone is still powered on, this consuming power.
I think for me it was up updating via OTA. Possibly it messed up some setting or the authentication tokens for Siri servers.
I hate myself right now. I ment to say, "when the iPhone is OFF." Wednesday while in hospital over night, I would turn phone OFF to save power, and it'd still lose 2-3%.
What I started noticing Wednesday night is that I lost percentage even when iPhone was OFF. Explain that one.
2-3% overnight while OFF seems excessive!
2-3% isn't actually that bad, in my opinion anyway. The power up/down cycle could have something to do with it or the percentage isn't as exact as we would like it to be. I personally turn the percentage off so I don't worry much about it.
I'm certainly clueless as to the inner workings of delta vs. full iOS (or Mac OS X, for that matter) updating, but... The download sizes of delta updates are obviously much smaller than those of the real McCoy (no offense to delta updates). Nonetheless, after performing a delta update via OTA, the iPhone behaves exactly as it used to after downloading a full-size new version of iOS via iTunes, as far as I recall. It's not a stretch of the imagination that perhaps Apple hasn't perfected the art of weaving the code it downloads from a delta update with the already-present code in the iPhone's current on-board iOS. JUST my $0.02!
If you turned the phone off/on several times while in the hospital, then maybe it was a combination of the power-up/-down cycles like owieh mentioned above plus the fact that you were in a hospital, which probably put extra stress on your iPhone's battery while it tried to get a good cellular signal while you had it on. Try the same power cycling at home if you're overly concerned (just to put your mind at ease).
I haven't noticed it, but that's probably related to more to my usage patterns - I'm plugged in often, so battery life is tough for me to measure. I have seen quite a few comments in the circles I travel about people saying it's much improved. Figures, the update that doesn't say anything about battery fixes, actually does fix the battery.
