We've talked about Mophie's Juice Pack rechargeable external battery cases for iPhone before; we did a review of an early model and have given you the news of the Juice Pack Plus for iPhone 4. We finally got our hands on a Juice Pack Air for iPhone 4 for review purposes, so now it's time to give you the skinny on how this battery pack works with the latest incarnation of the iPhone.
Design and size
Like the previous version for earlier iPhones, the Juice Pack Air for iPhone 4 comes with a USB-to-micro USB cable that is used for syncing and charging the case. The four LEDs that are used to indicate the amount of charge in the battery pack are still there, but have moved to the bottom of the case from the back -- I'm speculating that this was done to make the case thinner.
The older Juice Pack seemed somewhat flimsy to me, but the iPhone 4 edition seems to have been designed with more strength in mind. The case has a silver-colored band around the side to mimic the iPhone 4's stainless steel antenna, and comes in either black, red or white plastic. Installing the case is a cinch: you slide off the top of the case, slide in the iPhone 4 dock connector first, and then slide the top of the case onto the top of the iPhone. The weight of my "naked" iPhone 4 is 4.9 ounces (139 grams); the Juice Pack Air brought the total weight up to 7.3 ounces (207 grams). Without the Juice Pack Air, your iPhone 4's dimensions are 4.5 x 2.31 x .37 inches (115.2 x 58.6 x 9.3 mm); with the battery case installed, the dimensions swell slightly to 5.07 x 2.51 x .68 inches (128.8 x 63.8 x 17.3 mm). There's a photo of the phone and case side-by-side on the next page.
Of course, the Juice Pack Air adds some bulk as well as weight to the iPhone 4. The phone feels a bit more like a first-generation iPhone with the case installed, as it has a slick curved back. If I have one complaint about the Juice Pack Air, it's that I wish it had a textured surface. It feels quite slippery, and with the added weight of the battery I kept feeling as if I was going to drop it.
Using the Juice Pack Air
The main purpose for the Juice Pack Air is to allow you to recharge an iPhone when you're away from a power outlet, and that's where this case shines. Mophie says that the 1500 mAh pack will "virtually double" the life of your iPhone 4 or add up to 6 additional hours of 3G talk time. If you're the type of person (and I am...) who does more surfing than talking on your iPhone, you can expect an additional 9 hours of Wi-Fi surf time.
When your iPhone battery is pretty well drained, you flip a switch on the side of the Juice Pack Air to enable recharging. Mophie color-coded the switch so that it shows a small red band when the case is turned off that turns green when turned on -- a nice touch.
Where I find the Juice Pack Air to be useful is when I'm using my iPhone with geolocation-enabled apps like RunKeeper Pro or Geocaching. These apps have a tendency to suck down the battery quite quickly, and I've often worried about running out of juice while out walking or bike riding. Knowing that I can double the amount of time that my iPhone will stay up and running is a very comforting thought.
We have a white Mophie Juice Pack Air for iPhone 4 that we're going to give away to a lucky TUAW reader. To enter, all you need to do is leave a comment telling us what you'll do with all of the extra battery power you'll have. Here are the official rules:
- Open to legal US residents of the 50 United States, the District of Columbia and Canada (excluding Quebec) who are 18 and older.
- To enter, leave a comment telling us what you'll do with the extra battery life from the Mophie Juick Pack Air for iPhone 4.
- The comment must be left before Sunday, January 9, 2011 11:59 PM Eastern Standard Time.
- You may enter only once.
- One winner will be selected and will receive a white Mophie Juice Pack Air for iPhone 4 valued at $79.95.
- Click Here for complete Official Rules.