Cell phone cases that recharge the battery are worth a look

Nowadays, we use our cell phones for much more than making calls, and one of the biggest things is playing games.

Only a lot of heavy duty gaming can suck up your battery pretty quickly. That�s why, as a heavy cell phone gamer, I was excited to test three phone cases for iPhone 4 that actually can recharge the phone and extend your battery life. There are similar cases available for other cell phone models.

The first was the Case-Mate fuel lite. It�s $59.99 or $99.99 depending on the size battery you chose. Case Mate says the $100 version, with the bigger battery, can add up to nine additional hours of talk time to the iPhone 4 and up to seven additional hours of internet use and up to 10 additional hours of video playback. These kinds of times were consistent on all three cases.

I couldn�t go through the iPhone battery and the Case-Mate backup, even while watching movies, playing games, making long calls -- basically doing all the heavy lifting I could do.

The case is comfortable, soft and very much like the industry best Otterbox cases I�ve tried for this product. The Case-Mate is a big case and will add considerable size and bulk to the thin device (think Otterbox �Defender� series).

The Case-Mate, like the other two cases, allows you to use a mini USB cable instead of the Apple white charging cable. The mini-USB is a standard port used by lots of devices, so if you do need to charge up at the office, one of your co-workers is more likely to have that cable. Better, the Case-Mate passes iTunes and in-car iPod through the cable.

And lack of that feature was my only complaint about the Energizer "Energi To Go" cases. I tested one for the iPhone 3 and 3GS that was hard plastic and only covered the lower 2/3rds of the phone. It did the job but was not pretty at all. The iPhone 4 case ($69.99) was silicon, slim and absolutely elegant. It�s easy to toggle between using the battery or not, but it doesn�t pass through iTunes or in-car iPod through the mini-USB cable.

It�s a minor annoyance I guess, to slip the phone out of the case to mate with iTunes or listen to your songs in the car, but that�s why it�s No. 2 in this review.
The best charging case was the Mophie Juice Pack air ($79.95). It passes iTunes/iPod like the Case-Mate and it�s thin like the Energizer. It feels good in the hand.

A toggle button on the lower left, makes it easy to switch between charge modes, and you can press a button of the bottom to see how much charge is left in the case. I ran the iPhone battery to zero and the Mophie charged it back to 80 percent. When I drained the iPhone battery to 20 or 25 percent, the Mophie would get it back to 100 percent easily.

This is your gold medal winner from a group of three strong challengers. If I were a heavy iPhone user, I�d definitely grab one of these.