After the post on how to get maximum usable hours out of your iPhone through Settings tweaks, emails started coming in asking about if there is anything can be done to make the battery last. Since the battery is ‘built in’, iPhones and Touch devices have to be returned to Apple for battery replacements. Apple has posted that they expect the batteries to take over 300 cycles of charge/discharge before the ability to hold a charge (usable hours) drops dramatically.

Apple posted on their site a few tips to keep the battery in good condition – take a quick look, many are common sense and will keep you from having to be without your device in the near future while it gets it’s battery replaced.

Charging Tips

iPhone 3G cannot be charged with a FireWire power adapter or FireWire-based car charger. Make sure your computer is on while charging iPhone via USB. If iPhone is connected to a computer that’s turned off or is in sleep or standby mode, the iPhone battery may drain.

Maximum Battery Life

iPhone 3G offers up to 5 hours of talk time on 3G, 10 hours of talk time on 2G,1 5 hours of Internet use on 3G2, 6 hours of Internet use on Wi-Fi,3 7 hours of video playback,4 or 24 hours of audio playback5 on a full charge at original capacity. In addition, iPhone features up to 300 hours of standby time.6

Charge Cycles

A properly maintained iPhone battery is designed to retain up to 80% of its original capacity at 400 full charge and discharge cycles. You may choose to replace your battery when it no longer holds sufficient charge to meet your needs.

Let It Breathe

Charging your iPhone while in certain carrying cases may generate excess heat, which can affect battery capacity. If you notice that your iPhone gets hot when you charge it, take it out of its case first.