One of my pet gripes is the prevalence of Automated Task Killers for Android. In my view they do more harm than good. This is because Android memory management works a little differently to what people would expect.

Looking through the Google Play store, there is a proliferation of power managers, task killers, task managers, battery managers, battery extenders, etc. that are available to install. Some of these are pretty useful tools to extend your battery… however, contrary to what most people think, task killers can waste more battery than they save, especially if you don’t understand how Android works.

There might be a bit of history here as task killers were an important part of Android prior to the memory management improvements / changes introduced in Android 2.2 (Froyo). Prior to Froyo, task killers were an important addition to manage the applications on your phone but now there are more sophisticated ways to extend your battery life.


Android memory management

Android memory management is very different to Windows memory management. (Which given the prevalence of Windows, is how I suspect most people think about memory management.)
The underlying assumption with Windows is that it’s connected to mains power and therefore everything should be maintained running in memory.
Since Android is battery powered, the way it manages RAM is designed to minimise battery use. When an application is not in use, the application is suspended and will sit dormant using no CPU nor battery.
When the phone’s overall memory gets low, the Android OS shuts down the applications that have been least used. E.g. in reverse priority order.

The determinant in Android for battery management isn’t whether the application is loaded, it’s actually how many CPU cycles an application using.


Why automated task killers are inefficient

So using an automated task killer is inefficient for a few reasons…

  1. You are using additional CPU cycles (running the Task Killer) to either manually kill or “autokill” applications
  2. Since Android 2.2, most of these apps will re-launch straight away, again using additional CPU cycles and having limited effect of actually killing them
  3. When you want to open a commonly used application that could have been lying dormant in RAM, you have to re-load into RAM, again using more CPU cycles


There’s a “but”

But, I hear you say, I’ve been using an automated task killer and my battery life improved. This is generally due to poor coding practices in an application and/or a runaway process. While you’ve been blasting applications off your phone, you’ve probably also killed the one or two rogue apps that were actually the issue.

You are better off finding out which of your applications isn’t working properly and then stop using it. Or if you really want to use the application, know about it and use it sparingly.

A more effective way to find whether an application is behaving badly is to use a CPU monitoring app, such as Watchdog. It will give you alerts when your applications start to excessively consume CPU cycles so you can figure out what to do with the particular application.


What can you do?

Errmm. Well what can you do to extend your battery life?

I’ve got a HTC One XL. It’s an awesome phone but the battery life is terrible. There are many days where it is quite difficult to make it through one business day without having to recharge it. (However, having a massive screen & a 4g connection is always going to make battery-life difficult.)

Here are my tips.

  1. Watch for runaway applications.
    Watchdog is a good CPU monitoring app. You’ll be amazed as to what is actually using your CPU and its most likely not the applications you’ve been blasting.
  2. Get rid of rogue apps.
    Uninstall applications that are of limited value that are hogging your CPU. Bye bye.
  3. Use a battery management app.
    I use JuiceDefender to turn off features on my phone that drain your battery. 4g, wifi, bluetooth and screen brightness are generally the biggest culprits of draining your battery.
    Turning off your 4g connection whilst you are using Wifi can extend your battery by a lot.
    You can also just use the Power Control widget.
  4. Limit the number of widgets on your home screen.
    Is having live Facebook updates on your home screen really all that important?
  5. Limit the interactive features on your wallpaper / lock screen.
    Do you really need the wind blowing in the breeze of your background?
  6. Restart your phone occasionally.
    It will assist with the dreaded phone lag.


Anyway, task killers are generally a hot topic in Android forums. In my view they do more harm than good and you should move to a monitoring app rather than using a task killer. This can actually extend your battery life whilst improving the usability of the phone.

I’m keen to hear other people’s experiences and other people think. (I’m always on the lookout for a way to improve my battery life!)

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