Third Rail System (for iPhone 4)

Pros: The case itself it attractive, durable and thin, the battery really isn't too large, and the case does not pull off screen protectors like a lot of the others.

Cons: The battery does like a 40% charge, the battery is not reliable and it does very quickly, it's super awkward to use when the battery is on, it costs way more than it should, the case scratches the iPhone when taken on and off, the charge feature works lik

Summary: I ordered the case the day it was advertised on Cnet, as I thought it would make my iPhone's battery somewhat rival that of my old Blackberry. With a total cost of $100, this case was not worth it. The battery only gives a 40% charge when put on the phone. That is, when the case is actually working, which is sort of a rarity. Also, the battery drains itself very quickly, even when it is not getting used. So, it's not something you can keep in your car, just in case.

As of now, I still use the case, as the case it attractive and well built. As for the battery, I have not used it in months. Ultimately, spend your money elsewhere, as this case is not worth $100. I'd even hesitate to buy it for $50.