With the release of Windows Phone 7.5, Microsoft allowed applications to run even while you’re not using it. This is referred to as a background task or process. Every task, background or not, will consume a little battery power and potentially some data too. So why would I care to have a background task running on my device? Well, everyone is always looking for the longest battery life possible, and some of us are even looking at ways to keep data usage in check. Background processes could potentially wreak havoc on that. Let’s use WhatsApp as an example. The background agent would be used to keep a connection back to their server so they can quickly ping you with incoming chat messages. If the WhatsApp server doesn’t know where to find you, it’s going to have a hard time delivering the chat message. So having this background agent is a good thing! Now, if that background agent runs too frequently, or you have too many of them running, it could have an impact on your device battery.
In order to protect us from resource hungry tasks that may be running in the background, Microsoft put some restrictions in place. Basically there are 2 different types of tasks that can run on a Windows Phone device. The first is a "Resource Intensive Task" – this is where you need something done that takes more than average amount of time and processing power. These are only allowed to run when the device is plugged in, has a charge over 90%, the screen is locked, and can only run for 10 minutes at a time. This is great for doing a nightly backups for example. The other type of agent is a "Periodic Task" – this is used for a small amount of time, typically 25 seconds, and runs on a regular interval which is usually around 30 minutes, but may be as frequent as 10 minutes. These are used for quick updates to applications like location, or news. Microsoft has also set a limit on the number of background tasks possible. However, this number can vary based on device. They don’t say what the max will be, but they do mention that it "could be as low as 6".
For some applications it makes sense to have a background task that handles a simple task every now and then. However, not every application needs to run in the background. Further, you might not want a given app to run in the background. So how do you check which apps are running in the background, and how can you control or limit their impact? It’s actually very easy to manage background tasks, if A) you know that they are running on your device, and B) where to find them.
Simply open Settings, and swipe to the side so you are looking at Applications. The first item in the list under applications should be "background tasks". Tap on this see the list of applications that are running in the background on your device. If an app is configured to run in the background, you will see "on" under the application name. If you tap on an application, you can then turn off the agent. To turn the agent back on, you need to check the box that says "Turn background tasks back on for this app the next time I open it", and then go launch the application.
Take a close look at the list of applications that have background tasks and ask yourself if you really need that app to be running in the background. Remember, every task takes a little power. If you’re finding that battery life isn’t what it once was, you might want to turn some of the less than useful tasks off. Of course, everyone’s idea of useful is different. For me, I don’t see any need in having IMDB running in the background. Same for audible, LinkedIn, or any of the weather applications. In fact, I have turned off all the background tasks on my device. I would rather have the extra battery life and wait 20 seconds for the weather to update when I launch the app. But that’s just me. Experiment and find what you want to run in the background. As you install more applications, you will want to come back from time to time and check on the tasks, just to make sure that they correspond with what you actually want to run in the background.