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samcraig

macrumors P6
Original poster
Jun 22, 2009
16,786
41,983
USA
I've never been one to complain about smartphone battery life - especially the iPhone since ultimately - if it gets be through the day, I'm good. I don't care if I plug in at night if I'm at 80 percent or 3 percent.

And coming from the 3GS to the iPhone 4 - I did notice a slight improvement over battery life.

However - looking at a lot of usage reports (and a few people here in my office comparing during different times during the day) I did feel that my battery life wasn't as good as theirs. By afternoon - I might be down to 70 percent and they would still be as high as the mid to high 80s. A few into the low 90s. And most of our shared usage was the same - and most of the time the phone was "idle" on our desks.

I tried reboots/reset network settings, deleting apps & mail accounts/etc

So what was the difference? Silly really. I have 3 email accounts. One is via Gmail and is on push. That's my primary account and gets probably about 100-200 messages a day. I have a legacy AOL account and also a POP account from a website I maintain. The POP account gets lots of spam. The AOL account barely gets anything either way. Both these accounts were set to fetch every 15 minutes.

Like some of my colleagues. I switched my fetch to every hour.

For the past two days - my iPhone 4 battery has transformed. Sincerely. It's currently 1:40pm (been unplugged since 7am) and my % is 92%. Normally around this time - like I said - I would be in the late 70s.

That's SIGNIFICANT. And while I understand "why" - I have to say that I am a bit surprised that logging into two email accounts a couple of more times an hour uses THAT much battery. Approximately 20% for 18 additional "fetch's" for each account. That's roughly "using" 1% for each fetch.

So either AOL or my POP is dragging and causing more workload - or something else. Don't know. Don't really care.

Sorry for the long post. But in short, and it may seem obvious, but if you think you're battery is draining more than it should. It might not be multitasking. Or a bad app. Or many things. It might be something very simple like changing your fetch to hourly or manually.
 
Oh.. I also kept wondering why my usage seemed to be longer (decently significant) more than what I knew I was using my phone for. Alas - no doubt, all the logging in/out of mail was soaking that up.

Today I'm at 58 min of usage / 6:52 min of standby

prior to this - I would be about 2.5 hours of usage / same standby
 
The iPhone cell stack is known to be very aggressive about closing idle 3G data connections quicker than most phones, in order to conserve battery.

Unfortunately, that can mean a timed fetch might have to negotiate a new data connection with the tower, which uses more battery.

Moreover, if you're in the middle of a non-3G voice call, the phone has to obtain a 3G voice+data connection in the background, then invisibly switch your voice call over to 3G, all so the background fetch can go through while you're talking. It might even switch towers to do this.

This is expensive in battery and can cause a call drop for reasons unknown to you. It's a side effect of simultaneous voice and data under GSM.
 
Usage increases although not much when you are idle.

What is your actual real bonafied usage?

Marc

Well prior to making the switch - my real usage might be an hour - but it would indicate - let's say appx 3 hours. Which I consider to be pretty out of line.

Today (after the switch), for example - I have about 50 min of real usage (plus I am sure background usage) and my iPhone says 1 hr and 4 minutes.

And I am currently at 90 percent.

Standby is 8 hours, 40 min.
 
Well prior to making the switch - my real usage might be an hour - but it would indicate - let's say appx 3 hours. Which I consider to be pretty out of line.

Today (after the switch), for example - I have about 50 min of real usage (plus I am sure background usage) and my iPhone says 1 hr and 4 minutes.

And I am currently at 90 percent.

Standby is 8 hours, 40 min.

Wow you don't use your iPhone much.

Marc
 
Wow you don't use your iPhone much.

Marc

Actually I do. Most of my usage though isn't during the day except email. I am on my laptop for most of the day (lots of writing/con calls/etc). So I am using iphone when in a meeting and/or reading email from 7-5. But I use it heavily in the evening and on weekends.

Plus - I'm not one of those people that's constantly on my iPhone or any cell. It's a tool for me - I don't use it to constantly amuse me (not suggesting you do). Know what I mean, though? Some people on here are 24/7 iPhone users. I would say I am an average user with above average technical expertise.

Oh - and I also have an iPad at home which does more of the "heavy lifting" when lounging around...
 
I think that is pretty remarkable, I guess I wouldn't have thought it would have been that significant. I had fetch set on one of my legacy email accounts for 30 minutes and am going to set it to manual and see what impact there is.

Anyway, thanks for sharing.
 
I think that is pretty remarkable, I guess I wouldn't have thought it would have been that significant. I had fetch set on one of my legacy email accounts for 30 minutes and am going to set it to manual and see what impact there is.

Anyway, thanks for sharing.

Would love to know your results as well. And yes - pretty significant.

I'm now down to 77 percent. 2 hours of "real" usage; 13 hours 10 min of standby.

Much much better than I have been getting.
 
This is why you use PUSH with exchange instead of fetch, so that it's not setting up and tearing down data connections all the time.
 
This is why you use PUSH with exchange instead of fetch, so that it's not setting up and tearing down data connections all the time.

indeed. you just don't always have that option with email accounts. But any accounts you can't push - set it to the maximum fetch (1 hr) or manually. WORLD of difference
 
Good post, I just adjusted my fetch schedule to every hour rather than every 15 mins. I'll see if there is a difference, I'm sure there will be based on what you've seen. I wasn't worried about my battery life, but better is always good. Thanks for the tips.

Gmail does push though right?
 
Good post, I just adjusted my fetch schedule to every hour rather than every 15 mins. I'll see if there is a difference, I'm sure there will be based on what you've seen. I wasn't worried about my battery life, but better is always good. Thanks for the tips.

Gmail does push though right?

Yes. Gmail does push if set up as an exchange acct. Post your results when you have them
 
You're an excellent writer, and I think you've made it quite clear, but just to confirm, when you set fetch to hourly, did you leave your Gmail Exchange push set to on?

The only reason that I ask, is that it's common wisdom around these parts that Push is what kills your battery, not Fetch...

Thanks!
 
You're an excellent writer, and I think you've made it quite clear, but just to confirm, when you set fetch to hourly, did you leave your Gmail Exchange push set to on?

The only reason that I ask, is that it's common wisdom around these parts that Push is what kills your battery, not Fetch...

Thanks!

I left push on my gmail account. The only think I did was change my AOL and another email address (pop account) to fetch 1 hr vs the 15 min. I also did a hard reset (powered off by holding menu button and sleep button down for several seconds until the apple logo popped on

It could just be that my POP or AOL account was causing slow/long fetches - not really sure which is why I posted to see if others have can duplicate the adjustment with similar results
 
I agree, great write up Sam. I'm going to try this as well, I'll post my results in a couple of days.
 
I agree, great write up Sam. I'm going to try this as well, I'll post my results in a couple of days.

Great! I look forward to it.

Last night - I ended up having a measly 2.5 hours of usage - BUT - my battery was still at 75 percent. Previously, I would have easily been below 40...
 
Great! I look forward to it.

Last night - I ended up having a measly 2.5 hours of usage - BUT - my battery was still at 75 percent. Previously, I would have easily been below 40...

Why don't you just setup gmail (via web interface) to access all your mail accounts for you? That way you only ever have to deal with gmail alone.
 
Why don't you just setup gmail (via web interface) to access all your mail accounts for you? That way you only ever have to deal with gmail alone.

Good question. No "real" reason other than I like to keep things separate.
 
I left push on my gmail account. The only think I did was change my AOL and another email address (pop account) to fetch 1 hr vs the 15 min. I also did a hard reset (powered off by holding menu button and sleep button down for several seconds until the apple logo popped on

It could just be that my POP or AOL account was causing slow/long fetches - not really sure which is why I posted to see if others have can duplicate the adjustment with similar results
But what costs more battery: push or fetch?
 
But what costs more battery: push or fetch?

I don't know which technically costs more. I do know that poor phone signal and/or difficulty logging in/polling the account can suck the batter dry.

But I'm not sure there's a definitive answer - someone else can chime in. Of course - also depends on how much email you typically get too...
 
Right so what you are saying is: you have turned off some features that require your phone to do more in the background when idle, and battery performance has improved? Incredible!

I've had mine set to fetch manually since owning the phone (actually its was since the 3GS as I had useless battery life with it), its kind of logical that turning off features improve battery performance. Im surprised that you are so shocked by something so obvious. Although I agree that the battery gains are higher than expected.

I find I get fantastic battery performance with the following settings:

Wireless: Always on (auto connects to work and home as and when)
Location services: Off (switched on when needed)
Notifications: Off
Push in email settings: Off
Auto brightness: Off (have the slider at the halfway position)
 
Right so what you are saying is: you have turned off some features that require your phone to do more in the background when idle, and battery performance has improved? Incredible!

I've had mine set to fetch manually since owning the phone (actually its was since the 3GS as I had useless battery life with it), its kind of logical that turning off features improve battery performance. Im surprised that you are so shocked by something so obvious. Although I agree that the battery gains are higher than expected.

Disregarding your unnecessary snark - I'm not surprised changing (minimizing) settings affects battery life. If that's what you took from my original post, then that's your issue.

My surprise was at how SIGNIFICANT changing fetch from 15 min to an hour affected my personal battery life. In my opinion, there should be an affect - but not THAT drastic. After several days with JUST that change - I have increased my battery life by 30-40 percent by the end of the day. And it's pretty much all in my "idle" state. IE - using the iPhone is of course going to reduce battery (games, photos, reading, etc). It was the idle time that I saw great reductions in battery life.

I can see from the latter part of your post that you agree - it shouldn't be THAT much of a difference. So I was putting it out there to others to see what their results would be since many people are claiming to have issues with their battery life when comparing their usage to others.

I have brightness at about 40 percent - always have wifi/3g on. I have location services on. Notifications on. Auto brightness on.

I was "content" with my battery life - was just surprised that I wasn't getting "super" results compared to other posters.
 
I find I get fantastic battery performance with the following settings:

Wireless: Always on (auto connects to work and home as and when)
Location services: Off (switched on when needed)
Notifications: Off
Push in email settings: Off
Auto brightness: Off (have the slider at the halfway position)
Why would Location services have any impact on a idle iPhone?

Also, why would auto brightness off have a positive impact on battery life? Seems to me that keeping your screen at medium brightness would cost more battery than the iPhone auto dimming it when appropriate (it never sets the brightness above the threshold, only looks if it can set it lower).

Also, why isn't 3G Off part of your list? If there is one particular feature that eats unnecessary battery life then it's 3G networking. It only really adds anything for data speed: not for call quality and especially not when you are near a WiFi point.
 
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