Energizer AP1201 is the solutions on many Smartphone include iPhone 4 user sometimes got terrible problem. The main problem is short battery life. You are right from many resource battery life on iPhone 4 much better than previous version. I have test it and prove it. But that not solve all Smartphone user problem. For heavy usage using iPhone 4 we still need to get portable charger. So we can use it when iPhone 4 power almost drain.
There are a lot of portable charger outthere. Mostly using some connector or short cable. For some iPhone user, this one not practice and make iPhone Look weird :) But there are some enginer that give nice charger. Integrated Charger and Case. So portable charger will be fit in our iPhone. And Energizer AP1201 is another Rechargeable Battery Case for iPhone 4. Check it out this screen shoot. The design good enough. Very stylist and I like it (this is the most important for me). How Much is it? You can get Energizer AP1201 iPhone 4 rechargeable case that comes bundled with a USB charging cable is now available for $69.99 only, check more detail here
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