Sunday, November 18, 2012

How to fix poor iPhone battery life

My iPhone 5 wasn't making it through the day. I was disappointed, but after a few simple changes it looks like it could even last two days.

My usage pattern is that I charge over night, get up at about 6am, listen to podcasts for an hour going to and an hour returning from work.

During the day I make a few calls, and use a lot of Wifi data. On the way home I use a bit of LTE cellular data to catch up with news feeds.

With the changes below, as you can see from the Usage screen to the right, after 11 hours without a charge my battery is still at 74%.

Long life suggestions

  • Avoid polling for email. I was polling for GMail every 15 minutes, I switched to the GMail client (as I use Exchange for work email). So mail is pure push and it's instant.
  • Turn off LTE unless you're in a good LTE reception area and actually plan to use it. LTE is very patchy here and I've noticed the phone running hot in my pocket trying to contact cell towers.
  • Screen brightness under 50%.
  • Choose a carrier with good strength at your home and office. Phones turn up transmit power is signal strength is low.
  • Reset network settings: Settings>General>Reset Network Settings. I'm a little sceptical about this one but it forgets all those Wifi networks you've used once and stops the phone trying to join them again, unless you specifically want to.
Using Push instead of polling is the big one I think. Push is very efficient, it's a single TCP connection to Apple which all notifications come over (so I don't believe the number of apps that can push will make much difference).

Incidentally, all those tips you see about quitting applications that you aren't using are nonsense. iOS will only allow them to background for 10 minutes and then only for specific tasks like completing a download. The only exception is playing audio which you want anyhow.

Before the iPhone 5 I had a 4 (not the s). The battery was losing capacity after almost two years of daily cycles. The solution was to pay $9 for a replacement battery on eBay. It came with the tiny screwdriver and there are instructional videos on YouTube. It's easy and cheap to do.

I hope this clears up some mis-information I see around the place. Let me know how you go.


Here's how my phone looks after 27 hours of not being plugged in and normal use for me. That includes quite a few hours of internet and podcast listening but no tethering. If you think you have a problem it would be useful to compare your usage with mine by the time you drop below 20% battery.


alexsatrapa said...

Hello, random Internet stranger here.

I have Mail switched to "Fetch" on my phone and desktop: that is, the mail application will only check for new mail when I tell it to. I'm not interested in being interrupted by new mail. Incidentally, I also have the phone in silent or Do Not Disturb mode most of the time: the phone is strictly for my convenience, not everyone else's.

I get a day or two out of my iPhone 4 even with WiFi and Bluetooth left "on". I've told it to forget networks that I don't care about anymore, though I do run the battery dry quickly on "down" days when I'm constantly polling Facebook and Twitter for more external validation of my existence.

The greatest change to my iPhone 4's battery life (and my lifestyle, and my productivity at work) came about by simply turning off polling for mail.

It's interesting to see that you have consumption/heat trouble due to LTE coverage. I'll keep that in mind should I decide to upgrade.

Thanks for taking the time to add some sense into the discussion of iPhone 5 battery life problems :)

Peter Marks said...

Thanks Random,

I have seen people complaining about bad battery life so I thought it worth posting some specific details. As you say I think the culprit is mail polling and the repeated network connections that result from it.

I was polling for mail every 15 minutes. Big mistake.

As for bluetooth, I think it's very low power, particularly on iPhone 5s as they support version 4.

Best wishes,


VE9KK said...

Good morning Peter, I have the 4S and the battery life has been much better than my previous 3. I had heard about shutting down the app's that were not running did help nice to know that is but a myth. With the 4S I do have to plug it in on the way home from work as I am at around 30%. I too looked into the battery change out when I had my 3 and to me it looked a big long and drawn out for just a battery.
Thanks for the tips

Peter Marks said...

Replacing the battery in a 4/4s is pretty easy. I bought a kit on eBay and it came with the two alternative tiny screw drivers and a plastic tool for disconnecting the connector.

I think it was much more difficult withe the 3.

Gordon VK2UB said...

My experimental results. I ran the iPhone 5 for 12 hours, listened to 30 minutes podcast each way to/from work, viewed tweets on twitter and posts on, checked email (push - Exchange and iCloud), checked weather, etc:

Airplane Mode on, WiFi on: 86% battery left after 12 hours.
Airplane Mode off, LTE off, WiFi on: 54% battery left after 12 hours
Airplane Mode off, LTE on, WiFi on: 35% battery left after 12 hours

Your mileage may vary.

Peter Marks said...

Thanks Gordon, very interesting.

I think that Airplane mode would turn wifi off though.



Gordon VK2UB said...

No, you can turn WiFi on again after going to airplane mode.