Why do "Notifications On" use battery life even when they don't do anything?

Did a test on my iPad after installing 4.2

Though I'm sure the same happened before the upgrade.

I always keep a very close eye on my Battery Life and notice when things are not as I expect them to be.

I did a test the other night.

Charged my iPad right up to a solid 100% battery, nothing in the multitasking tray but with "Notifications On" in the settings area of the iPad.

Also there is no email pushing or pulling going on. That's all turned off also.

Under the notifications area it there were only 3 things which had the normal 3 options turned on.

And during my test period (24 hours) I had no notifications come through, so they were in effect inactive.

Anyway...................

iPad with full 100% charge and Notifications turned on in settings and only 3 programs with their own notifications turned on (game centre being one of them)

The Charge went down from 100% to 83%

During that 24 period the iPad was just sitting there unused. I did not even touch it once during the test as to my knowledge no notification came through. Certainly there was no sound or on screen clue to anything at all.

So, nearly 20% of batter gone in 24 hours of just sitting there.

I then turned off notifications under the iPad's general settings.

And left the iPad for a further 12 hours untouched.

The battery power then went from 83% to 82% (which is arguably nothing)


Can anyone explain why this may be the case?

Does having notifications on mean these apps are in some way still hunting for data over wifi every so often?

dave420 said:

That is my understanding of how it works. If notifications are enabled then the iPad has to maintain a constant connection to be ready to receive notifications. It doesn't matter whether you actually receive notifications or not, since the constant connection will be maintained. On the plus side it doesn't matter how many applications are actually enabled to receive notifications since only one connection will be kept open.

Click to expand...

Ah ok, that makes sense.

For me, it makes no sense to leave notifications turned on overnight or whilst I'm away at work, burning away perhaps 15% or more of the battery over a 24 hour period even without even using the iPad.

It does confuse me why Apple have not made a quick and easy way to turn on and off notifications when you are using the device.

For games and such like.

Perhaps someone can explain this to me?