What uses battery while in sleep mode?

[JLangevin]

First off, hello everyone! Im new here, hopped over from the DroidForums.net with my new iPhone. Glad to be here.

Secondly, I have been experimenting with my battery life, and it is very good I must say. Once I followed all the suggestions to increase the life i have been very happy, but one thing I noticed is that something using the battery while the phone is alseep, and here is why I say that.

I was testing the battery and went to bed with exactly 20% battery left, and usage at 6hrs 48min. When I woke up, the phone was at 15% and the usage jumped to 7hrs 14min.

Now, i have my email fetching every 30min. I slept from roughly 12:30am until 7am. Thats nearly 30min of phone usage in a 6.5 hour span. The phone fetched 13 times. I dont know what would be using this "Usage" while the phone is off. All of my background apps were closed, Im anal about not leaving things running.

So, does anyone have any idea?

Additional info that may be useful
-WiFi was off. I leave it on during the day, but off at night
-3G was left on
-All apps closed
-Alarm clock set
-Notifications off
-Words with Friends seems to give me badges even though I have the notifications off... could this be it?

 

[shown]

Hi
You have done a good question, it’s really interesting. If you get any good reply, so please let me know. So I’ll also get some good idea.
Thanks for your future help.

 

[CalifJewls]

Most likely your email and select apps are using up your battery. It is a mini computer, as with a laptop, there are always things running in the background. With apps such as Facebook it still sends you a notification, so I would assume Facebook is using some battery to do that, as with other apps also.

It's recommended that you do not let your battery run below 20%, you should be plugging your phone in and charging it to 100% daily whether it's at 30%, 50%, etc. and once a month, let your phone fully discharge until it shuts itself off, then fully charge it to 100% without interruption. I personally plug my iPhone in all night, every night.​