Does your iPhone battery never last as long as you'd like despite our tips to give it more juice? Do you need additional backup power? If so, then you need a battery pack.
Griffin's TuneJuice, which I tested this week, gives an iPhone as much as 2 hours to 3 hours and 30 minutes of extra talk time depending on the type of batteries used. I purchased it because it uses AAA batteries and I wanted to add it to my emergency supplies. I'll keep it primarily for hurricane season, but it will come in handy during any emergency or power outage.
The TuneJuice isn't as complicated as Just Mobile's Gum Pro. It doesn't offer an on and off switch or a battery level indicator, and it won't fully charge the iPhone either. Yet, its lack of dependency on power sources like a computer, A/C outlet, or USB conversion makes it a worthwhile backup solution. You just need to make sure you have an ample supply of AAA batteries on hand. Hopefully, you won't have to use it for extended periods of time since the batteries could start to get expensive.
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 TuneJuice to my iPhone and let it charge until its batteries were depleted. As a result I got about 2 extra hours of battery life with heavy iPhone 3GS use.
That extra time makes the TuneJuice a good choice for any active iPhone user. The $30 price tag is reasonable and it makes for a must-have iPhone accessory for anyone who likes to be prepared for the unexpected.