Help How I extended the battery life from 10h to 28h and find buggy apps sucking battery life


Hi Guys, i've been reading up on a few Android forums including this one for some time and ironing out some problems on the HTC Desire HD phone. Thought i'd share some of the findings with you that helped me increase the battery life from 10 hours to 28 hours.

This HTC Desire HD is running Froyo 2.2 from Australian Vodafone purchased November 2010

The battery would go flat in 10 hours or less with light usage: an hour or two of Internet + gReader, less than half an hour of phone calls, and half an hour of running a game or two
1) 100% busy CPU
2) Up time = Awake time

I come from a Linux/Sysadmin background, so i use this approach to troubleshooting

A number of settings were changed from their defaults prior to this testing and lots of apps were installed during the 1 month honeymoon period of unboxing the phone and realising there is a problem

100% CPU Busy
To overcome the 100% CPU Busy problem, I found this thread and followed the instructions to enable USB Debugging

This saved a lot of wasted juice due to a bug sending the CPU into an infinite loop

Up time = Awake time
Next, to find which app was keeping the phone awake when it should be sleeping (Uptime = Awake time)
Uptime and Awake time can be viewed from Settings > About phone > Battery
Awake time should be a small fraction of Up time. If not, then something is wrong - possibly an app keeping the phone awake when it should be sleeping

Some related posts are here

I spoke to HTC support and their only advice was to remove all apps, do a factory reset and go from there. You have to remove all apps first because the phone will automatically restore all apps from the SD card.

The apps I had installed were
Advanced Task Killer, aLogcat, Angry Birds, AppBrain, Battery Left, eBay, Dropbox, Evernote, File Manager, gReader, HTC Sync, K9 Mail, mythmote, Retro Camera, Skype, Swype, Swype Installer, Smooth Calendar, System Panel, Talk to me, Terminal Emulator, Tram hunter, Winamp, Wordpress.

Some of these apps have a System Permission "prevent the phone from sleeping" which can be found in Apps > Menu > Remove App > (app name) > scroll down the bottom to Permissions

The following apps had the "prevent phone from sleeping" permission were
eBay, Dropbox, Evernote, GMail, HTC sync, K9 Mail, RockPlayer, Skype, Swype Installer

Steps taken to factory reset

  • Export all Contacts: People > Menu > Import / Export > Export to SD card > Phone
  • Uninstall: ATK, aLogcat, Angry Birds, AppBrain, Battery Left, Dropbox, eBay, Evernote, File Manager, gReader, HTC Sync, K9 Mail, mythmote, Retro Camera, Skype, Swype, Swype Installer, Smooth Calendar, System Panel, Talk to me, Terminal Emulator, Tram hunter, Winamp, Wordpress
  • Settings > SD & Phone storage > Factory data reset > Reset phone, Erase everything
  • After phone reset: Sync to auto, set up no accounts. NO facebook, flickr, twitter etc.

Steps taken to restore phone

  • Set wallpaper to HTC Wallpapers > Black
  • Set Brightness to Auto, Timeout 30 seconds, Auto Rotate off
  • Set Sound > Vibrate Feedback off
  • Restore phone contacts from SD card (did not sync with Facebook)
  • Synchronisation is default ON
  • Locking the screen will put the phone into Sleep mode
  • Enable screen lock sounds

A running tally of the Uptime/Awake time is listed here as I installed apps one by one. I would install an App, reboot the phone to reset the counters and try to use the phone as little as possible during the hours/day

Install Swype:, log in, download installer, ver 1.1.16059

  • Enable USB debugging to work around 100% CPU busy
  • Sync enabled
  • Wifi Enabled
  • After charging and using the phone periodically over one night:
  • Up time: 17h32
  • Awake time: 00:53

Install Facebook app

  • Reboot: 8m uptime, 6m awake time. The first 5 minutes of the phone booting is usually awake time
  • Check again: 13m uptime, 8m awake time.
  • Syncing automatically: Facebook, Stocks, Weather
  • Up time: 4h42
  • Awake time: 00h45

Set up Android Marketplace

Install/Add Google account, GMail and Sync

  • Checks mail
  • Reboot phone
  • Uptime: 5h20
  • Awake time: 00:36

Install Battery Left app

  • Displays which App or System is using the battery when the phone should be in Sleep mode
  • Reboot phone
  • Up time: 00h30
  • Awake time: 00h03

Add Flickr and Twitter Sync

  • Check all synchronise settings are 1 hour or more
  • Settings > Accounts & sync > (select each account) > Update Schedule > 1 hour or more
  • Reboot
  • Up time: 00h46
  • Awake time: 00h05

Install K9 Mail app

  • Has System feature to Prevent phone from sleeping
  • Version 3.404
  • Set up my mail account: Push notifications, IMAP, TLS always, Check folders every hour
  • Reboot
  • Up time: 00:42
  • Awake time: 00:05

Install gReader RSS reader app

  • Version 2.0.0
  • Synchronisation options: Auto update: Wifi Only, 1h interval, Items limit: 200
  • Notifications: Enabled. Sounds, Vibration off
  • Cache: Phone, all defaults
  • All defaults
  • Up time: 00:40
  • Awake time: 00:04

Install Smooth Calendar widget

  • Version
  • Up time: 12:08 (overnight)
  • Awake time: 02:08

Install RockPlayer app

  • Version 1.6.0
  • Can prevent phone from sleeping
  • Up time: 09:11
  • Awake time: 01:19
  • Reboot phone
  • Up time: 01:49
  • Awake time: 00:30

Install Evernote app
  • Version 2.5.1
  • Can prevent phone from sleeping
  • Up time:
  • Awake time:

Install skype app

  • Version
  • Up time: 00:58
  • Awake time: 00:19

So far so good, battery life hit a high of 28 hours after a bump charge (charge the battery with phone on to 100%, switch phone off while still charging till the orange light turns green)


Thread starter
I haven't found it yet - haven't reloaded all of the apps from before, i'm still working on it.

I can say that the apps I have installed and tested above were definitely not causing the problem though


Wow! That's some testing, no doubt! I'll visit this topic again, curios. I gave-up, I just charge it all the time, I have over 50 apps installed!:D
hi great post
i have had my htc hd for seven days now and am really getting fed up with it due to battery life(
i hope to try what u said above just a question
the apps that are able to prevent the phone from sleeping? can i change there permissions so that they do let the phone sleep?!


Thread starter
Hi, not all apps that "prevent phone from sleeping" will actually do it. Most of them only use this feature while the app is running, for example Skype or Evernote while the app is open in the foreground.

I don't think you can change the permissions of an app