I wrote a generic post here about improving battery life on a smartphone. That will definitely get you there, but how do you know for sure what’s hammering your battery? That’s sometimes a tough question, but a few tools help.
I mentioned System Tuner Pro before. It can tell you a lot about how your system is running. I especially find it useful in tracking down run-away or misbehaving processes, as well as killing errant processes. It’s how I found out that gsiff_daemon ate my battery early on. But System Tuner won’t tell you exactly what’s happening with the battery itself.
The best Android battery usage tool is BetterBatteryStats (BBS) by Sven Knispel. This app is worth every penny. It provides a detailed list of battery usage by kernel process or application, data usage, as well as CPU use history. Run BBS for a day and you’ll learn about every battery hog on your device.
After following the steps in my previous post, especially turning off all but essential syncing, location (tracking) services, etc., I still had battery usage that seemed high. I suspected that some process was waking the Galaxy S3 frequently enough to affect the battery time. You can see this by going to Settings -> Battery:
Then tap on the graph at the top.
Under the graph details the screen shows network signal quality over time, Wi-Fi use, awake time, screen on time, and charging periods. The graph clearly shows periods of heaviest battery drain, which you can correlate to the activities shown at the bottom.
Here’s the trick: The major awake and screen on periods should correspond most of the time. If you have a lot more awake time than screen on time, somebody may be phoning home in the background more than desired. BBS can ferret out the offender(s). The first thing to check on BBS is the CPU states.
If the vast majority of time isn’t spent in deep sleep, then you may have an issue.
I checked the Alarms:
and Network screens:
Although not depicted in these screenshots, I found that Yahoo! Mail had about 6-8 times the number of wakeups as the nearest competitor and it transferred a significant amount of data. Thus, it was hammering the CPU as well as the radios. Unlike the Google Mail app, there is no way to control Yahoo! Mail’s syncing behavior. So, I decided that the battery hit wasn’t worth the minimal value of the app and uninstalled it.
The net result of going through the entire general process and then using BetterBatteryStats to ferret out the last battery-life offenders proved dramatic. When I started, I was hitting about 30% battery remaining after about 10-12 hours of moderate use before cleaning up. Now as you can see from the screenshots, I’m at 75% of battery remaining after 16 hours of moderate use. That’s a dramatic difference gained simply by taking control of the screen brightness and the radios, yet without taking extraordinary measures with apps like Juice Defender.
Getting the most out of your smartphone battery takes a bit of knowledge and effort, but the results will prove well worth it.