If you think that the bigger capacity of the iPhone 4 (as compared to iPhone 3Gs) still cannot satisfy your desire for longer talktime, maybe this Exolife casing from ExoGear can help you.

At only 59 grams, it gives you 1500mAh extra juice for your iPhone 4. With it smart management, it can turn on or off when needed. Behind it, it has a indicator for the battery and the casing is made of Polycarbonate.

Right now, it is up for pre-order. The Black casing will ship end of this month while the white casing will ship end of September. The cost of this exolife casing is USD89.95.

Click Here to Check Out Exolife for iPhone 4

BTW, it has casing for iPhone 3G and 3Gs too.
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