Over the last few weeks, my husband and I have been given the opportunity to try out several of the latest iPhone battery pack cases on the market today. He helped me write this review of the four cases we tested out.

FastMac iV:
Good: The iV really extends battery life. Ryan used it for a few weeks, and noticed that he would get to the end of the day with normal usage and just barely be getting to the phone power. The iV can also be used to recharge other USB chargable devices, like a bluetooth earpiece. It also has a very convenient flashlight that can be used to improve photo quality in dimmer lighted situations among other things. Unlike many of the other battery pack cases, the iV uses your iPhone charging cable to charge up, and you don’t have to remove the case if you use the Apple universal dock.
Bad: With more power comes a bigger battery that makes it big and bulky, especially if you keep your phone in your pocket. Another thing we found was that when the iV is low on battery it will continuously alert you by vibrating if your ringer is off or beeping if your sound is on. We’ve contacted FastMac and they said that it is normal, and suggested removing the case. They also suggested only using the iV as a charger rather than a case, and only connecting it to the iPhone when you need a quick charge. It does not fully encase phone so the top is not protected if phone is dropped.

It’s big and bulky, and not our first choice for carrying around in a pocket all day, but, it’s spectacular battery life makes it great for when the kids want to watch movies or play games or if you’re going to be away from a charger for a weekend away. It’s great to keep in your purse or laptop bag for those quick charge emergencies! They do also include a free screen protector and in iPhone headphone adapter cable so you have microphone and iPod music controls just like the iPhone headphones. It comes in handy if you forget your iPhone headset and can find your iPod earphones!

2G only: $79.95

Universal 2G, 3G, 3Gs & touch: $99.95

* Optional belt clip is available for purchase from FastMac $19.95

**UPDATE 11/17/09: @rjbrady has just informed me that the second battery pack case has failed on him. The iV has started losing it’s charge very quickly. It used to last all day, and now it’s lasting half of the day. The issue I mentioned with the vibrating when the battery pack is out is constant. The case does not stay off when he turns it off. Not sure if there is an issue with the power button, but will be contacting FastMac tomorrow for possible solution!

inCase Power Slider
Good: The inCase Power Slider is fairly streamlined. This case extends battery life to last all day with moderate use of phone and Internet. I’ve actually owned this one for several months now. I purchased it when I upgraded to the iPhone 3G. It was the only iPhone battery case that I knew about at the time. It uses (included) a mini USB cable to charge, which is the same USB cable used with most digital cameras. This makes it easy to charge without wall outlet adapter if near computer. The Power Slider does not alert you when it’s out of battery. It just switches to phone battery.
Bad: I have had it for 6 months and it was already losing charge time. It was great at first, but with daily use and charging, it seemed like the battery life was diminishing. The matte finish was peeling off, which was only cosmetic, but just didn’t look as pretty anymore. My phone also seemed to lose some reception with this pack. When I removed the top part I typically gained one bar. The speaker phone could not be used unless I removed the battery pack. It would cause some sort of interference and make noises on the phone and person I was speaking to couldn’t hear me. I also had a lot of trouble with syncing the phone with the case on. I followed the instructions word for word, and it still would not connect.

*inCase has recently discontinued the 3G Power Slider due to many of the complaints it has received, but is promising a new version out just in time for the holidays. Despite inCase no longer carrying this item, the 3G Power Slider is still available from many online retailers.

MSRP $79.95 at many retailers

Mophie Juice Pack Air
Good: The Juice Pack Air is very streamlined. It’s thin so it doesn’t add a whole lot of bulk to the phone. The case fully encompasses the phone so it’s protected all around, except the screen. I’ve been using this case for the last couple of weeks, and even took it with me to Blog World Expo. The battery definitely lasts through the day with a lot of use! While at the conference, I was able to text, tweet, check my email, use the internet and talk on the phone all day without worrying about my battery dying. The trick, I learned, is to use your phone battery until it’s at about 20%, and then turn on the battery pack to re-charge the phone. It worked out really well this way. Unlike the Power Slider, I didn’t experience any interference while using the speaker phone, nor did I notice any reception loss when the case was on.

Bad: The Juice Pack Air uses a (included) micro USB cable instead of a mini for charging. Make sure you have your cable because you more than likely won’t be able to just bum one off of your neighbor at the conference.. but don’t fret. If you happen to carry an Amazon Kindle DX2, you can use that cable to charge your Juice Pack Air too.

$79.95 at Mophie’s site, the Apple store or other Apple certified vendors!

Case-Mate Fuel:

Good: The Case-Mate Fuel extends battery life very well, even with heavy use of the iPhone and it’s services. Like the iV & the Juice Pack Air, the Fuel has an on/off button so you can control when your pack is on or off. It also has a belt clip attached so you don’t have to put it in your pocket or bag. The great thing about the clip is that it allows the case to turn so you can wear your iPhone vertically or horizontally. After 10 days of continuous use, the clip is holding up very well. The clip is not detachable though, so if you don’t like the idea of having a clip, this probably isn’t the case for you. The Fuel uses a mini USB cable for charging, so it should be fairly easy to find a cable to charge up if you forget yours.

Bad: The Fuel doesn’t protect the top of the phone. It also has bright blue LEDs on the front that are always on when the pack is turned on. This uses unnecessary battery power, and makes it hard to have on in darker places (i.e. the movie theater).

$79.99 at Case-Mate online store and other retailers

After testing out the various cases, Ryan has decided that the Fuel is the best one for him for a daily use case, where I have chosen the Mophie Juice Pack Air. Check out the various iPhone battery cases on their websites using the links in each review or in your local retailers to see which one would best fit your usage needs!

**UPDATE 10/29/09: The Fuel has stopped charging this week. No idea why. Searched Google for anyone else with similar issues and came up empty. I’m in contact with a rep from Case-Mate who has requested I send it back to him. No troubleshooting suggestions. We’ve both tried plugging the phone into our computers, our Apple Chargers with the correct USB cable, and I’ve tried both his and my iPhones. No luck. Will update again when I get some sort of resolution.

**UPDATE 2: The Fuel was sent back, and deemed to be a bad battery. No replacement unit was ever sent for further review.

**UPDATE 3: We really needed to get my husband an iPhone battery case, so for Christmas 2009, I purchased him a Mophie Juice Pack Air. Based on all review units sent to us, this was the case that I felt was the best option for us.

**We want to thank FastMac, Mophie and Case-Mate all for sending us their cases for this review.