How to Extend the life of your iPhone battery

Low battery – two words you never want to hear. Banish them with these tips.

You Will Need

* An iPhone

* A computer with internet access

* An external battery extender

Step 1. Lock iPhone

Lock your iPhone down when you're not using it. Press and hold the Sleep/Wake button on the top edge of the phone to enter lock mode.

Step 2. Update software

Keep your iPhone up-to-date. Software upgrades keep your battery performing at the highest level.

Step 3. Turn off Wi-Fi and 3G

Turn off Wi-Fi and the 3G cellular networks unless you need to browse the internet. You can switch off Wi-Fi in Settings and 3G options are under the Network tab in Settings. When it's time to browse, choose one or the other – you don't need both.

Step 4. Limit maps and video games

Limit interactive maps and GPS tracking. Turn off location services in General Settings and use mapping applications only when needed. Also limit 3-D video-game playing, which rapidly consumes battery power.

Step 5. Use Airplane Mode

Use Airplane Mode – found in General Settings – when you're in an area with minimal cellular coverage. This turns off the automatic search for a connection, but allows you to use all non-wireless features.

Step 6. Manually check your mail

Manually check your mail. Automatic message retrieval eats battery power. In Settings, access Fetch New Data and choose "Manually."

Step 7. Dim screen

Dim the brightness of your iPhone screen. In Settings under Brightness, manually drag the slider to the left to dim the screen as much as your eyes desire.

Step 8. Run it down

Run your iPhone through a full charge cycle at least once a month to sync the battery's fuel gauge with its state-of-charge – essentially "reminding" the battery of its full capacity.

Step 9. Buy a battery extender

If you're willing to shell out the extra dough, buy an external battery extender. Most slide onto the back of your iPhone and run around $100.