Android Battery Saving Tips

April 30th, 2011

Don’t run a “task killer” app
A lot of people think a task killer or app killer app will save you battery life. In fact, you’ll find it regularly in the top 20 for top free apps in the Android Market. When I bought my first Android phone in 2009, the T-Mobile salesperson recommended I install it. And I’ve heard of cases in which salespeople will actually install a task killer app while you’re at the store. Let me be clear about this: task killers will not save you battery life. If they do, all it means that you have a bad app installed that, instead of being killed constantly, should be uninstalled. At best, task killers will do nothing for your phone. At worst, they will cause instability and glitches. For more details, read the following:
Android Task Killers Explained: What They Do and Why You Shouldn’t Use Them
FAQ: Why You Shouldn’t Be Using a Task Killer with Android
Why you don’t need a task killer app with Android.

Don’t bother with all the little things
So after I did quite a bit of research and found out task killers are not only useless but actually detrimental to the proper functioning of your Android phone, I read all sorts of tips espousing little things you can do to save battery: dim the screen brightness, turn off GPS, switch to Edge only (not 3G), turn off automatic syncing. Most of these things all help a little bit but not really enough to make it worth the trouble. And, in the case of GPS, sometimes they don’t help at all. GPS, for example, isn’t really on even if it’s “on” unless you’re using an app that actively uses GPS (e.g., Google Maps, Google Navigation, Yelp). If I constantly dimmed the screen and then made it brighter when I needed it and turned off syncing and synced only when I needed it, I could eke out maybe an extra hour or hour and a half of battery life. It seemed a lot of maintenance for very little return.

Use Juice Defender
It took me a year and a half of using Android before I stumbled upon and finally tried Juice Defender. This app easily doubled my battery life. I used to have my phone run from 7:30 AM to 11:30 PM at night but with only 15-20% of my battery left when I plugged it back into the charger at night. With Juice Defender, I had 50-60% of my battery left at night. There are a lot of things Juice Defender can do if you get the paid versions, which allow you to tweak settings even further, but on a basic level with the free version it turns off your data when your screen is off and then turns it back on again when your screen is on.

Even though I would highly recommend JD to anyone with an Android phone who also wants to get the most out of her battery life, there are a couple of annoying things with the program. Firstly, it insists on having a huge icon in the notification bar all the time. Well, there’s a setting to not keep it there, but apparently if you don’t keep it in the notification bar the Android OS might accidentally turn off Juice Defender to free up RAM. Secondly, it takes a few seconds for data to turn back on after your screen is on. This last little niggle led to me uninstalling Juice Defender and opting for another alternative.

Or just turn off data when you don’t need it
You kind of have to think about your own phone-using lifestyle to see what will make more sense to you—turning data off every time your screen is off (Juice Defender) or just manually turning off data when you don’t need it. For my lifestyle, it makes a lot more sense for me to turn data off manually. I’m grateful for the work the Juice Defender folks are doing in showing me how to save battery life, but the extra few seconds to wait for data to turn back on were just too much for me, the way I use my Android phone.

I basically have some periods in which I’m using my phone pretty heavily (but only in short spurts) for data and then longer periods when I’m not using my phone for data at all. So I have a power widget on my home screen for toggling data. When I’m about to use data, I turn it on. When I know I won’t be using data for a long period of time (2-3 hours or more), I turn it off.

I hope people have found these tips helpful. Post if you have any questions. (Any attempts to promote task killers will be immediately deleted as spam.)

I rooted my first Android phone (the MyTouch 3G) within a month of owning it, and I rooted my second Android phone (the MyTouch 4G) within a day of owning it. Rooting is sometimes an easy process and sometimes a bit complicated, but in my experience it’s always been worth the effort. My sister-in-law came to visit and complained that her almost year-and-a-half-old Droid (the original, not X or Incredible) is glitchy, has poor battery life, and is just not that responsive. She wants to get an iPhone but is not yet eligible to switch over subsidized. So I offered to root her phone for her.

Now, I’m always hesitant to try to fix people’s computer problems, and the same goes for Android phones (which are basically really small computers). On the one hand, I know their experience can be better. On the other hand, I know that a successful migration of any kind or major overhaul involves time and some testing. Most of the time, people want a quick fix. And if you tell them it’ll take a long time, they’ll feel guilty about using up your time and just say “Oh, it’s okay. Don’t bother.” Really, though, they’re still not happy with whatever situation they’re in. So I always try my best to find the balance between quick fix and thorough fix.

So I got her to promise me not to install Advanced Task Killer (which was probably responsible for at least some of the glitchiness), I backed up her bookmarks and apps, and then I began to root her phone. I tried to follow the Droid full update guide at the Cyanogen mod wiki, and I ran into a couple of bumps along the way. First of all, the sbf_flash file for Linux gave a segmentation fault, but the guide actually offers a separate download if that happens, so I used that. I also tried to flash the ClockworkMod Recovery, but when I tried to reboot into recovery mode, I got stuck on the Motorola logo, so I had to take out the battery, flash back to SPRecovery, install the Cyanogen rom, and then flash ClockworkMod again.

Immediately, she was impressed with the upgrade. I told her it was Gingerbread, and she had no idea what that meant. I told her it’s basically the next version of Android. She didn’t really seem to care. She just liked the cleaner interface. She liked the battery life displayed when she’s about to unlock the phone. She found it a bit more responsive. The only problem is I forgot to back up her Angry Birds data, so she’d have to play all the levels all over again. So I did a bit of Google searching and experimenting and found out I could get the data out of /data/data/com.rovio.angrybirds/files/highscores.lua, /data/data/com.rovio.angrybirdsrio/files/highscores.lua, and /data/data/com.rovio.angrybirdsseasons/files/highscores.lua. To do it properly, you have to beat at least one level in each version of Angry Birds. Then, instead of copying the file and changing permissions, you should cat one file into the next:

cat highscores.lua > /data/data/com.rovio.angrybirds/files/highscores.lua

Overall, I’m surprised that she liked it. Usually I think of rooting as for power users who like to tinker with their smartphones. It’s good to know end users can enjoy the benefits of a rooted phone as well. Extra bonus is that when you boot up the phone there isn’t that annoying “Droid!!!” robotic voice announcing the name of the phone. And I know she can stay on Cyanogen RC 4 until Christmas when I see her next, and still be ahead of the OTA updates to the Droid. Or she may just get the iPhone 5 by then.