Are you an active iPhone user? Or a Twitter and e-mail addict? Does your iPhone battery never lasting as long as you would like it to? Want emergency backup power? Regardless of the circumstances, you need a battery pack.
Just Mobile's Gum Pro, which I tested this week, gives an iPhone a little more than two additional full charges. I have no complaints about it and I'll never leave the office without it.
The Gum Pro offers some advantages that other battery extenders (such as the Mophie Juice Pack Air or the Energizer AP1500) do not. For starters, the Gum Pro is smaller, more compact, and offers a lot more battery for the buck at 4,400mAh and just 5.3 ounces. the Gum Pro charges via a standard Mini-USB port and a gauge that shows you the charge status of the Gum Pro--or, just watch for the charging screen on your iPhone to disappear once the Gum Pro empties. Recharging the Gum Pro takes approximately 3 hours.
In my tests, I started with my iPhone 3GS at 100 percent charge and waited until it showed about 20 percent of its own power left. I then attached the Gum Pro to my iPhone and let it charge to 100 percent again. I recharged my iPhone twice on a single Gum Pro charge. On the third charge, the Gum Pro charged the iPhone 3GS an additional 25 percent before throwing in the towel. The result: I got two extra days (plus some) of battery life with heavy iPhone 3GS use.
That extra time makes the Gum Pro the obvious choice for any active iPhone user. The $60 price tag--$20 less than the Mophie or Energizer--larger battery, and the fact that it is compatible with other devices (including iPods or any device that charges from a standard USB port) make it a superior backup charger.