We've therefore put together some simple tips that will allow you to enjoy your iPhone for longer by increasing its battery life.
Firstly if you carry your iPhone around in a case charging the phone while it's in that case may generate more heat than is healthy for your phone. Overheating is bad for both battery capacity and battery life, so if your iPhone gets a little toasty when you charge it in its case, take it out of the case in future before you charge it.
You might not know that Bluetooth consumes power even when it's not being used. If you're not using a Bluetooth device, make sure Bluetooth is turned off, or if you do use one, turn it off once you've finished. Just go to 'Settings' > 'General' > 'Bluetooth' and use the On/Off switch if necessary to turn off Bluetooth.
Just as Bluetooth consumes power even when you're not using it, so does Wi-Fi, so turn it off when you're not using it. This time go to 'Settings' > 'General' > 'Network' > 'Wi-Fi' and use the On/Off switch if necessary to turn off Wi-Fi.
Activating the Auto-Brightness function allows your iPhone to adjust its screen brightness based on ambient lighting conditions. This can be easier on your battery than cranking it up and leaving it set to a bright setting. To activate this feature, go to 'Settings' > 'Brightness' and use the 'Auto-Brightness' On/Off switch if necessary to turn it on.
Our last tip concerns listing to music. Having EQ (equalizer) on when you listen to music can make it sound better, but it uses more processing power and hence reduces battery life, therefore turning off the equalizer will help your battery last longer. If you've added EQ to tracks in iTunes via the Track Info window and you want to retain the EQ from iTunes, set the EQ on your iPhone to flat. Since you're not turning off EQ, your battery life will be slightly worse, however your songs will sound just the way you expect them to sound. To turn off EQ go to 'Settings' > 'iPod' > 'EQ'.
According to sources at Apple, a properly maintained iPhone battery can retain up to 80% of its original capacity after a full 500 charge / discharge cycles.