While the battery life of the iPhone 4 and 4S is known to be pretty good, some people need that extra juice for long trips or long periods of being away from a charger. New iPhone cases from PhoneSuit will look to improve the smartphone's battery life and offer some protection at the same time.

Eugene Kim, a junior analyst of consumer electronics of PC Magazine, said the device offers excellent battery life in a compact design with a relateively low price of $80. He said cons of the device is that it's a bit heavy, but said it more than doubles the power of the iPhone 4 and 4S for not much money.

"The PhoneSuit Elite may not be the thinnest iPhone case, but it matches the longest battery life of any case we've tested, and does so in a relatively slim and classy package," he said. "The makers of the PhoneSuit Elite also included a thoughtful replacement for the top part of the case and some screen protectors in the package."

PhoneSuit's website said the device can provide a full charge to the iPhone, meaning it can be very useful to people whose phones frequently die on them. For iPhone 4S cases, this device can come in very handy for users.