When we talk about Android battery life and its performance, there are plenty of best practices in the Internet. I decided to make my own guide, maybe someone will find it useful. This is not a step-by-step solution, you can use any of the following advices in whatever combination that seems to fit you (for example, you can try to improve stock ROM without flashing a custom one).
So, you are ready to tweak your green robot. Let’s see what you can do:
Prerequisites: device dependent.
Root access is essential when it comes to Android tuning because it is really hard to improve the system without full control on it. The process of rooting will not be explained here as there are plenty of guides, just open google and search “how to root “. And as for root access management app, I strongly recommend SuperSU by Chainfire.
Prerequisites: custom recovery (I recommend TWRP).
Almost all of the major vendors are selling devices with their own Android-based firmware (Samsung, for example). The main target of this firmware is stability, it’s really hard to crash one. As stable as it is, vendor firmware usually lacks performance and is overbloated with preinstalled software. And this is where XDA-Developers portal comes to the rescue. Most of custom Android ROMs are built with battery life in mind, so you can find one with largest community (like CyanogenMod) or the one with some unique features (like ParanoidAndroid) or whatever. It would be wise to read some forums first, whether that particular ROM you selected has any critical bugs. If well and no bugs, read installation instructions carefully and proceed with your flashing process. I prefer SlimKat as a daily driver for my Nexus 5, it is rock stable, fast and has good battery life.
Prerequisites: custom recovery.
Even if a custom ROM is not enough for your needs, there is another way to improve your setup – a custom kernel. There are some examples of significant performance and/or battery life increase. One good example is Boeffla kernel for Samsung Galaxy S3. There is no better custom kernel that I can recommend, you should read and choose for yourself. The music stuttering issue in SlimKat ROM, which has been reported by some users, can be cured by flashing custom kernel as well.
Prerequisites: root, busybox.
If you need to tweak a parameter or two in your ROM’s kernel (without flashing a new one), there is a nifty app in the Play Store called Trickster MOD. It can help you to change governors, i/o schedulers, cpu clocks and other weird looking stuff. Not all devices and kernels are supported, so check the release notes first. For advanced users only, it can damage your device.
If you rarely check Accounts section in your device settings, you may occasionally find out that Google account tries to literally sync everything. Syncing process lies in the background and has a substantial impact on battery life. Feel free to uncheck all that you don’t need to be synced (For example, if you don’t use Google+, uncheck Google+ contacts). It costs you nothing, your device doesn’t even need to be rooted, yet many people don’t know or don’t care about this little trick.
This great application has two main features that may come in handy. First, it can create and restore backups. No, really. Just set up a scheduled run to backup all user apps and sync it with Dropbox to be safe. And then, if you change the phone or flash a new ROM, install TB, select backup folder and hit that restore button. Please exclude system apps from the process, it can end up with weird Android behavior. And now the second handy feature. Every ROM, stock or custom, probably has some apps that you don’t need to use. For example, if you use Google Camera, you don’t need the stock one. You can freeze unused apps in system settings but they will remain on your device eating /system partition space. TB can physically delete system apps, though you should proceed with caution. First you should check with Google, like ” unused system apps”.
However, I prefer another approach. I just open newly downloaded zip file with WinRAR and delete unused apks from /system/app and /system/priv-app folders. For advanced users only, it can damage your device.
To be continued.