Extend iPhone / iPod battery lifespan

Apple claims that properly maintained iPhone battery will keep up to 80% of its original capacity even at 400 full charge and discharge cycles. So, the question is how to maintain and charge iPhone battery to prolong its life? Following are a few simple iPhone tips, first five are the most important:

    1. Make sure that you fully recharge iPhone / iPhone 4 / iPod Touch battery at least once per month (fully recharge means charging the battery to 100% and then completely running it down).
    2. Don't drop the battery charge to low.Battery cell has its own safe-voltage-limit (~ 3 V). iPhone battery is vulnerable to damage if the low voltage limit is crossed.
    3. To prevent failure, never store the battery fully discharged. Apply some charge before storage, and then charge fully before use..
    4. When possible avoid frequent full discharges. Instead, charge the battery more often. There is no concern of battery's memory when applying unscheduled charges.
    5. Avoid iPhone / iPhone 4 / iPod Touch from both overheating (> 35° C )and undercooling (< 0° C). The optimal temperature for IPhone is 22° C. The elevated temperatures hasten permanent capacity loss for iPhone battery.
    6. Free iPhone / iPhone 4 / iPod Touchfrom its leather or any other case when charging the battery. Those cases prevent adequate ventilation, and cause extra temperature rise while charging.
Useful way to safe iPhone / iPhone 4 battery life is to turn off 3G, WiFi and Bluetooth connectivity.. The fastest way to do this is to reach Airplane Mode in the Settings menu:
    1. Tap Settings from the Home screen.
    2. Select Airplane Mode and set its option to ON.
    3. Tap the Settings button to return to the main Settings screen.
    4. Press the Home button to return to the Home screen.
One additional way to save the iPhone / iPhone 4 / iPod Touch power is to dim the screen. The iPhone / iPhone 4 has a sensor to automatically dim. However you can reduce the brightness by applying the Global Settings from the main Settings menu:
    1. Tap the brightness option.
    2. Drag the slider down to reduce the brightness which will use less battery power.