Battery drained 9% just idle while I slept

[NovemberWhiskey]

When I went to sleep, I had just unplugged my iphone and it was at 100%. When I woke up about 8 hours later, my percentage had dropped to 91%.

The only things that happened on the phone were that my alarm rang a couple of times, and i received one text message.

I have push email turned off, wifi, brightness down, nothing else seems to be eating the batteries. Is this normal?

 

[Knowlege Bomb]

Doesn't seem too bad. I have yet to run this experiment but I wouldn't be disappointed with 9% idle usage in an eight hour period.

 

[outphase]

There's still a connection to the cell tower. Also, there has to be some power usage while simply being on. 1.1%/hr is pretty good for idle time.

 

[iMacDragon]

My standby usage seems to vary quite a bit, depends a lot whether 3g is on or not too.
today mine was about 9% over ~9 hours, I've had it as high as 20, which I was a little concerned about, and as low as 4-5% when on 2g.

 

[Eso]

Did you restore from a backup?

I restored a new 3GS from my original 2G and noticed very poor battery performance as well. One night I ran the iPod with the screen locked until the battery died and it only lasted 9.5 hours (rated for 30 hours). It's rated for 300 hours of standby, but at 9%/8 hr yours would only last for 90 hours on standby, which isn't that great. However, I have since restored the iPhone as a new phone and the battery life has seemed to improve (I've also turned 3G off when it's idle). I have half an hour of use and 13 hours of standby and I'm at 90% at the moment.

I would try emulating their Battery Tests which one mode of dedicated usage to compare to their numbers.

 

[DaGreat01]

Why dont you just leave it plugged in over night?

 

[UngratefulNinja]

Doesn't seem too bad. I have yet to run this experiment but I wouldn't be disappointed with 9% idle usage in an eight hour period.

I agree. I noticed last night while I slept 8 hours my iphone dropped 8%. I don't think 1%/an hour is bad at all

 

[Knowlege Bomb]

Why dont you just leave it plugged in over night?

This is the one great mystery of the iPhone crowd that still stumps me. Not sure I'll ever understand...

 

[MacFan782040]

What is defined by "standby time"?

From Apple's website: Standby time: Up to 300 hours on the 3Gs

If assuming standby time is not in Airplane mode, and you have the battery at 100%, then wouldn't it only drop .33% for each hour?

 

[Hydroxs]

Apple states up to 300h of standby time so about 1% every 3 hours

 

[Knowlege Bomb]

Apple states up to 300h of standby time so about 1% every 3 hours

Which, in my experience, is bullocks.

 

[GfPQqmcRKUvP]

10% is normal usually, but I don't know for your situation.

I did a battery test

-WiFi on
-Location on
-Fetch 30 min
-Push mobile me everything
-Push notifications
-Spotty cell reception

10% in 8 hours.

 

[Hydroxs]

Which, in my experience, is bullocks.

actually i do get around 3 hours for every percent

 

[Knowlege Bomb]

actually i do get around 3 hours for every percent

Congrats. That's your experience.

 

[NovemberWhiskey]

Why dont you just leave it plugged in over night?

I usually do, but last night I just happened to leave it unplugged on my nightstand.

But that is besides the point. The point is that it seems to have drained a lot for just 8 hrs. If everyone is getting that type of draining, I guess it is normal.

Afterall, maybe the alarm was draining it more than I thought. I am a heavy sleeper.

 

[choiboyogg]

yea i get about 1% an hour as well....

 

[Hawkwind]

Checked just before putting my 3Gs into sleep mode last night...64%, checked again 8hrs later when I woke up, and it's 62%.
Solid 3G signal
Wi-Fi - on
Location - on
Push - off

I'd hazzard a guess that results vary depending upon the battery state i.e. 100% - 90% drop happens quite quickly. The middle of the battery is a bit more robust.

 

[DaGreat01]

I say everyone should just turn off their % meters!!!

 

[alangrehan]

I say everyone should just turn off their % meters!!!

Does it really matter... you're starting the day with 90% battery power...

Just leave it plugged in overnight...

I've never gotten more than 2 days on a full charge with any mobile phone I've ever owned... With the size of the screen, 3G, etc the iphones battery performance is pretty awesome!

 

[sammy2066]

Are you saying I'm gonna have a poor battery life if I restore from my 2G backup? I HAVE to restore from my old backup, any workarounds for this?

 

[trainguy77]

I have heard that having tabs open in safari can affect battery life.

 

[Eso]

Are you saying I'm gonna have a poor battery life if I restore from my 2G backup? I HAVE to restore from my old backup, any workarounds for this?

If you are happy with the battery life you get, don't worry about it. Personally, I also restored from a 2G backup and was getting worse battery life than my 2G and was not happy. When I say worse, I mean just a bit worse, I usually averaged about 5 hours of mixed use (very little use of cellular data, however) and a day and a half of standby. However, it was disappointing since the performance was less than that of my 2G and significantly less than the advertised battery life.

Having restored, battery life is greatly improved and I am much more satisfied.

I have heard that having tabs open in safari can affect battery life.

Pretty much complete crap. This comes from the fact that Safari will run in the background which allows it to load up pages in the background. It will also keep the browser and the pages in RAM until needed.

Now, keeping anything in RAM will not use more battery power (RAM itself will take some battery power just to operate, but whether free space or used by an application, it is the same).

An application that is not actively processing anything will have virtually no load on the CPU (verify by observing your desktop computer idling at 0-1% CPU usage while idle). The only circumstance in which the browser will use more battery power as a background process is when it is loading a page, which takes all but a few seconds.

Now, if you have a page that constantly refreshes itself, like a page of sport scores, it could potentially drain your battery. The question is whether or not Safari actually allows pages to refresh themselves while in the background - especially if the screen is locked. I highly doubt this is the case - it's very poor design - and testing could verify what is going on.

 

[t0mat0]

I'd say it was quality of connection to cell tower. Having a weak signal can really change the rate of standby battery use. A way to test this - put it on airplane mode overnight and compare.

 

[critic81]

I just did a similar test last night

This is exactly when i went to bed

This is exactly when i woke up

A little under 8 hours idle and it dropped 16%. That is with 3G, Wifi, Push, Exchange google sync, mail fetched 1hr, location on, bluetooth off.

The other shocking thing is that i didn't touch the phone and it had almost an extra half hour of usage on it. Where the hell did that come from. If it fetch every hour then i can see like an extra 8-10 minutes of usage but still. HALF HOUR of usage while idle. What the hell is it doing?

 

[MadDog31]

I just did a similar test last night

A little under 8 hours idle and it dropped 16%. That is with 3G, Wifi, Push, Exchange google sync, mail fetched 1hr, location on, bluetooth off.

The other shocking thing is that i didn't touch the phone and it had almost an extra half hour of usage on it. Where the hell did that come from. If it fetch every hour then i can see like an extra 8-10 minutes of usage but still. HALF HOUR of usage while idle. What the hell is it doing?

Could there be an app that is getting stuck? I've heard that could be the issue. I had a 20% drain the other day at the office (bad signal but it's never caused that much drain) so I did a reset and the next day was much better...like 3% or so.

Just an idea, otherwise I'm not sure.