This post and all its comments were migrated from Artem's personal blog beerpla.net when Android Police launched. If you would like to visit the original post there, please click here.
It's not a secret that my Sprint HTC Hero has been having trouble keeping battery charge - by the time I came home from work, the battery level would oftentimes be at 10% or the phone would be simply dead.

One would give up and accept this futility but I had 2 reasons to keep trying to figure out why:

  • my co-worker's battery would consistently hold twice as much charge as mine - by the time I was at 50%, he was at 75%
  • a wide range of responses on Internet forums and blog posts suggested some people experienced excellent battery life, while others, like me, did not have as much luck
I received feedback from many people that the solution outlined here has helped them double their battery lives not just on their Android phones but also their Pres, Windows Mobile, and others. These people, like me, did not realize the drastic effect of the settings described here on battery life.

I thought I tried everything:

  • I kept WiFi and Bluetooth off when I didn't need them (I even got an app that turned WiFi on and off on schedule - Timerriffic; unfortunately until Hero gets Android 2.0 we won't see automatic Bluetooth scheduling)
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  • I tried to use the Spare Parts app which provided insight into battery usage history. I did not, however, find out anything significant
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  • I tried to avoid using GPS altogether - at one point Spare Parts told me GPS usage by Google Maps, Camera, and Bump were 5-6 hours each, even though I turned the GPS off. I think it's a bug in Spare Parts itself or what Android was recording but it made me paranoid.
  • I switched to using Handcent SMS due to the bug in default Message app (which was later fixed in the firmware upgrade).
  • I got a task manager (Advanced Task Manager) to see what apps are running and make sure especially heinous is eating up my resources. It would also automatically kill long running apps and certain apps I know I don't use and which I can't uninstall, such as IM, Gmail (I use Mail), and Finance.
  • On some days, I stopped using the phone altogether, just to see how long it would last. The result, however, was the same.

Nothing worked. Consistently, my phone would run down to 80% by the time I got to work and by about 3pm, it would be at 50%.

The Solution

Finally, a few days ago, when comparing my phone with my co-worker's, I noticed he didn't set up automatic email checking, opting in for the manual method instead. I, on the other hand, set up my email the day I got my Hero and never revisited the settings since. "How much power can downloading emails suck out?" I thought. Boy, was I wrong…

This solution is for people using the Mail app - not the Gmail app. The Gmail app uses the push method of getting emails - not pull, but doesn't suit my needs, which is why I am using the Mail app.

Turns out a LOT. I had 3 email accounts and they were checked at the following intervals:

  • my gmail was being checked every 5 minutes - I wanted near real-time notification but could not even fathom the consequences at the time
  • my beerpla.net account was hit every 15 minutes
  • my Plaxo work Exchange email fired every 30 minutes

In order to change these intervals, load up each email account's inbox, click Menu, find Settings, go to Send & Receive and then Set Download Frequency.

After I set each email account to check every hour instead, my battery life improved dramatically. To be fair, I watched the battery use for the last 3 days without changing my usage habits and recorded the results.

Here they are:

  • by the time I left for work in the morning, before the change I would oftentimes be between 85 and 90% battery. After the change, I was at 95-97%.
  • by lunch time, my phone would usually run down to 50-60%. After the change, the battery had 75-80% juice.
  • by 9-10pm, after I came back from work, I would usually need to put the phone on a charger because it was <15%. After the change, I was at least at 50%!

The Side Effect

Lately, I started to realize that having email notifications pop up this often was actually more distracting than useful. I was losing concentration and constant context switching made me less productive.

The fix for my battery problem was, incidentally, also the fix for my concentration problem.

Conclusion

Be very much aware of your email polling intervals or they will suck all the life out of your phone.

I would love to hear about your experiences with tweaking email settings and the effects those tweaks had on your battery life, as well as other dramatic Android battery saving tips. Feel free to share in the comments.