Friday, 9 March 2012

Scarce resources 2 - Battery

Look, I've got very little battery left, so please listen carefully. I need you to

There are few things more frustrating than finding that the powerful Android phone in your hand is suddenly quite useless because it has run out of battery. Batteries are improving, but they are struggling to keep up with the demands of bigger, brighter screens, faster processors, and function-rich apps.

My HTC Desire came with a 1400 mAh Li-Ion battery with a claimed life of 360 hours on standby. I suppose that if you didn't even receive a single call, and if you never turned on the screen, the battery might conceivably hold out for 15 days. But we don't buy smartphones to leave them on standby. We want to use them throughout the day, and not only to make and receive phonecalls, but to send email, read books, listen to music and lead our social media lives. I have learned how to make my battery last all day, and in this post I'll explain how.

You'll find many apps in the Android Market that claim to prolong the life of your phone's battery. But the only sure way to extend battery life is to use less of the functions that consume power. Among the battery-saving apps, the only one that appeals to me at all is Tasker ($/€ 4.49) which automates control of almost anything on your phone in response to signals such as time of day and location. However, I confess that I haven't even tried Tasker.

WiFi and data connections
As I explained in a previous post, I never use the data connection offered by my mobile supplier because I refuse to pay for their data plan. But web browsing and other data transfer is generally held to consume less battery on WiFi than it would on a mobile data connection. If you have a new phone and you don't have a data plan, immediately go from the homescreen menu to Settings > Wireless & networks and make sure that Mobile network is unchecked. (The screenshot below is from the Android 2.2 Froyo settings menu.) If you leave it on, your phone will use the network even if you don't have a data plan, and you'll get a very nasty shock when your next bill arrives.

Turn Mobile network off if you don't have a data plan.
What does eat through the battery is hunting for a WiFi connection, so if you are going to be out of range of a known WiFi connection for any length of time remember to turn WiFi off. I use Free Power Widget (free) to toggle WiFi off and on. In the screenshot below, WiFi is on. I have also installed a very useful little utility app, Wifi Status (free), which flashes up a reminder in the notification bar if WiFi is turned on and the phone is unable to make a WiFi connection.

I use Free Power Widget (top) to toggle WiFi, ringer, screen orientation and screen brightness.

Your phone's display is an obvious draw on power, and one that can be easily controlled. I set the screen timeout to 2 minutes (in Menu > Settings > Display). I've found this to be the shortest delay that does not quickly become irritating. Some apps, such as my e-book reader, FBReader, for example, allow you to override the timeout while you are using the app.

Screen brightness can be also controlled from the Display settings, and it is possible to turn on automatic adjustment. This increases screen brightness in bright ambient light, and reduces it again in shade or darkness to conserve battery. But I find that the automatic adjustment sets the brightness higher than I need, and I use Free Power Widget to toggle between low brightness, high brightness, and automatic. In the screenshot above, it is on automatic, but I generally leave it set to low. If I find myself squinting to see the screen I know where to tap to change the setting. Some apps, like FBReader and the NewsRob RSS reader, have a Night reading mode, which consumes even less power and reduces the risk of irritating your partner when you read in the middle of the night.

GPS and Bluetooth
Keep GPS and Bluetooth turned off at all times, unless you really need them. Apps that require GPS, like Google Maps and My Tracks, turn the GPS on automatically when you run them.

If you follow the advice above, you should normally be able to get through the day on one full charge, provided you don't spend hours watching videos or speaking on the phone. But performance will obviously vary with usage and between devices, and battery life is always a key consideration when choosing a new phone.

A final word of advice - don't forget to put your phone on charge overnight.

Next post: Be nice, share.