Incredibly poor iPhone 5 battery life whenever 3G is activated, why?

This isn't a minor flaw, this is an eggregious gaping bug. I just paid $950 SGD for what is supposed to be a top of the line phone and this thing has the worst battery life I've ever seen in a smart phone.

Not to say that signal strength is a valid excuse but it also isn't relevant here. I'm in the middle of a big city with full bars.

I also forgot to add that I set my screen brightness very low.

Really? Why is that? You can't expect a $950 phone to just "work" out of the box?

6.0.1 doesn't even mention battery life problems.

I exchanged my phone today after much hassle and difficulty. I'll update anyone that cares on whether or not that worked.

So I swapped my phone and the battery drain problem is still there. From 7.30 PM (when I unplugged it with a full charge) to about midnight it drained to 33% with really quite light use. Just some emails and texts, no calls. Overnight it drained to nothing.

This is either a software problem or there is a huge batch of defective batteries in the US and Singapore (at least) and they have done nothing to take the bad batteries off the market.

I tend to think it's software though because besides the fact that the battery drains quickly the phone is always hot as if something is really taxing the CPU even whent he phone is doing nothinng

I have all my notifications and location services set to a minimum. I don't run apps in the background. I haven't done much with this phone at all and it never lasts through a single work day (not the old one or the new replacement). I never do gaming.

All of that said because its' only happening to some people it must be an app... but which one?

I don't know if the issue is "100% related to cellular data" or not. The battery life is better on WiFi only or no data at all but it still isn't great by any stretch of the imagination.

The battery life is just atrocious on two phones now. Apple: Acknowledge and fix!

That's very helpful. My CPU is bouncing between 4% - 15% while i'm just looking at the app and not touching it. The battery state indicator does not agree with the built in one. When I opened it said 90% and the built in indicator said 97%. Built indicator still says 97% and now the app indicator jumped up to 95%.

Is there another app you can recommend that shows data usage? I would like to see if something is just sending or receiving data non-stop and that might be the casue...

Mine lasts perhaps 30-45 min at 100% and barely any use with cellular disabled. I will try this app. Thanks.

I will check this data app and see if it is sending lots of data when it shouldn't be.

Thanks.

Well I did a test with this new exchanged phone and the apps you recommended. With cellular data disabled the battery life is 3 - 4 times longer. It's "good" but not "great". I still feel like time that is classified as "usage" should be "standby". I got about 9 hours usage and 21 hours stand by.

I ran the two apps you recommended and at no time did I see excessive data use or CPU use. However, a couple times I had to turn on cellular data just for a few seconds to check a map or an exchange rate and the battery drop started again immediately. No excessive data usage observed other than that it seemed every time I turned on cellular it would instantly register 1 MB even if I did something htat should only use a few KB. When the battery was almost dead I left the cellular on for a little bit but did not notice any additional data beyond the first megabyte. However, the phone does get warm on the back whenever cellular data is on even if the phone is just idle. Can the cellular data chip be bad?

I was really surprised not to any excessive data usage or CPU usage. This makes no sense.

I did not track it or expiriment so carefully with the first phone but yes I exchanged it due to the battery issue.