iPhone Battery Life: Fiddling with screen brightness
After several months' use my iPhone 5 is already beginning to show signs of reduced battery life. In my opinion battery life was never as good as on the iPhone 4S, even from the perspective of a one-year-old 4S compared with a new 5. Recently, though, I have been running out of juice after only a few hours' use. I am a heavy user of wifi and cellular and my phone is in almost constant use when I am out and about. In short, I am probably the battery developer's worst nightmare.
I have tried all the tricks. I make sure to close applications not in use, particularly those that keep checking for data and especially those that use GPS. A navigation app such as TomTom will run your battery down in short shrift if left running. I also switch off wifi when not in use and, most of the time, I can manage with Bluetooth off.
My experience, however, is that the biggest battery drainer is the screen. I have been in the habit of relying on auto brightness but recently I have noticed the level is unnecessarily high most of the time. Whenever I check the brightness control in Settings I find the blue bar almost all the way to the right, irrespective of the ambient conditions.
This week I decided to switch off auto brightness and choose a manual setting which is acceptable in all but the sunniest conditions. I find I can get away with around 20% brightness most of the time and this has led to a dramatic improvement in battery life.
I am still experimenting with the settings but 20-25% seems adequate in current dull winter conditions. No doubt I will have to crank it up a bit in the summer. So far I am impressed with the results in terms of improved battery life and I will report back after a few weeks' experience.
by Mike Evans, 9 January 2013