Welcome back to this series of battery saving tips. If you haven’t already read Part 1, please consult there for beginner tips on saving battery on your Android device, which may be applicable to other smartphones as well. This article, Part 2, will attempt to address intermediate level settings which may help battery life. Please note that your mileage may vary.
Social network updates: If you use the Android Facebook, Flickr or Twitter application, you may have notice there is an option in the menus to sync in the background. By enabling this, the application creates a background ‘service’ which periodically creates a network connection invisibly. This can drain battery so it is recommended that if you do want to use auto-sync, set it to a reasonable time period, say once or twice a day, unless you are a social networkaholic. Note that if you have an HTC Sense UI phone, there is also an option to periodically sync updates from Facebook and/or Twitter, but it syncs more information than the standard Facebook application, as Sense also shows in-depth photo/status updates on a user by user basis. If you have a large amount of contacts and a high auto-update rate (ie. every few hours), this can be a substantial drain on your battery. The built in Picasa integration in Vanilla Android gallery downloads pictures on-demand, so does not update in the background.
Other program background services: Depending on what programs you run, many of them also have a similar background facility. Examples include news readers, podcast managers and others, which also use the same method of checking for updates in the background. This is generally OK, but keep in mind there is a strong correlation between data transferred and battery use. For example, let’s say your news reader is set to check every few hours, but most of the time it doesn’t find any new articles, the battery drain will be minimal as the data transfer is small. Also note that 3G usage generally uses more power than Wifi transfers, although both will still drain your battery substantially. If you want to test this out, use a program like EStrongs File Explorer and connect to a network share on your home network. Transfer a large file (few hundred MB or a few GB) and you will see that the extended radio use will destroy battery life, but of course this is an extreme and rare example. I’ve also found that the HTC Sense UI itself uses a big chunk of resources to exist, which manifests itself in memory usage, CPU usage and slower speeds, but damn it’s pretty.
Chat programs in background: In addition to the built in GTalk program (normally called ‘Talk’), there are a host of third party messaging programs which support many other protocols. I will be writing a roundup of these soon, but note that by running in the background, that they will use some small amount of battery as they constantly check for new messages. The only program I have found which addresses this is eBuddy, which has a delayed transmission mode, reducing can reduce update speed up to 15 minutes to reduce battery drain. The drain can be noticeable in some instances. There should be no reason to run multiple chat apps for the same protocol.
Background Tasks / Services: This one is tricky because the way that Android is design renders task managers obselete. Having a large amount of free memory does not necessarily mean your system is running better, which is a mistake many people make, coming from Windows environments. The program suspension and resumes should happen seamlessly, taking minimal resources. However at times, there are badly created programs which may cause issues, or if you have a carrier-branded phone that loads all kinds of useless things on startup. In cases like this, a Task Manager may be required to monitor these background programs, but exercise caution, as killing tasks without understanding their purpose can cause problems with your phone. I will write an article on this later on, as it can be tricky to figure out which apps are required for proper phone functioning.
Wifi Sleep Mode: In the Settings => Wireless & Networks => Wi-Fi Settings => Menu => Advanced => Wi-Fi Sleep Policy, there is an option for the Wireless radio to sleep when the screen turns off, never when plugged into power source and never full stop. I personally leave mine on never when plugged in, but some people have reported noticeable gains from setting this to ‘Never’. This may be due to Wifi using less power overall than data transfer over 3G, but some trial and error will usually yield a conclusion.