The Apple iPhone 3G's battery life has been a topic of some debate - but it's not all Apple's fault.

Because the iPhone's battery isn't user replaceable and lithium-ion batteries inevitably degrade a little every time they're recharged it's vital you get the most out of iPhone's non-replaceable battery while it lasts.

The key way to maximise your iPhone's battery life is to know that if you iPhone is less active, the longer the battery will last. So if you're always playing games or watching videos - both processor-intensive tasks - don't be surprised to see the red battery low icon sooner rather than later.

But there are also some background processes - such as 3G signal polling, push email, Wi-Fi, Bluetooth, even audible keyboard clicks - that draw a lot of power from the battery.

Do you really need any feature to be in an always-on state? If the answer's no, then turn it off and enable it only when you need it.

10 ways to get better battery life

1. Store and use the iPhone at room temperature

The iPhone functions well between 0 degrees centigrade and 35 degrees centigrade (32-95° F).

You should ideally store your iPhone in conditions between -20° C and 45° C (-4° F to 113° F).

The best battery life environment for both usage and storage is room temperature, approx. 22° C (72° F).

So keep your iPhone out of hot places - such as the glove box of a car - or especially direct sunshine.

2. Turn off Wi-fi

If you don't need to use Wi-Fi then you will get better battery life by turning it off and then enabling it when you need it.

• Go to Settings
• Click Wi-Fi
• Click Off

3. Change Mail autochecking from every 15 minutes to every 60 minutes

• Go to Settings
• Click Mail
• Click Auto-check and widen the interval or turn it off completely

4. Turn off Bluetooth

• Go to Settings
• Click General
• Click Bluetooth
• Select Off

5. Reduce the display brightness

• Go to Settings
• Click Brightness
• Drag the slider to the left to reduce brightness

6. Enable the display Auto-Brightness

• Go to Settings
• Click Brightness
• Switch Auto-Brightness to On

7. Lock the iPhone

Locking the iPhone as soon as you've finished using it will turn off the display and stop it making persistent calls while it's in your pocket - both of which draw battery power. Simply click on the Sleep/Wake button on the upper right hand of the iPhone until the display dims.

8. Turn off Keyboard Clicks

The noise keyboard click make actually uses up precious power - as well as being irritating! To turn off keyboard clicks:

• Go to Settings
• Click Sounds
• Switch Keyboard Clicks to Off

9. Enable Auto-Lock

Better still, if you can get into the habit of locking your iPhone yourself simply turn on the Auto-Lock feature:

• Go to Settings
• Click General
• Click Auto-Lock
• Select a duration before the Auto-Lock kicks in
  
  

10. Turn off the music equalizer (EQ)

The iPhone's audio equalizer uses a lot of battery juice and is not really a useful feature unless you're trying to sell a rubbish hi-fi in Dixons (RIP). Turn it off:

• Go to Settings
• Click iPod
• Select EQ and click Flat