There are two electronic devices that I never leave home without: my cell phone and my iPod. I hate being without either; worse than that, I hate when one dies on me when I forget to charge it. So I was pretty excited when I got the chance to try out mophie’s juice pack air, a new add-on device for my iPod Touch that claimed it would just about double the battery life.

I’m not normally one for protective cases—whether it’s my phone, iPod, or other gadget—because they can detract from the device's style. But I actually like the mophie case. It kind of makes me feel like I’m using some sort of Super iPod. (In reality, it doesn’t actually add that much bulk/weight to the device. And if it gave me a few extra days’ worth of juice, it’d be completely worth it for me.)

So I slipped on the case and plugged it into my computer’s USB port, charging both devices simultaneously until they were at full charge. You can tell they're done when the four blue LED lights on the back of the mophie case are fully lit.

That’s all there is to it. Just unplug your iPod, plop in your ear buds, and hit the road. You’ll know your mophie device is working because the battery icon on your iPod will indicate that it’s charging. And you can see how much juice is left on your mophie at any time by pressing the button to the left of the four LED lights on the back. (Oh, and if you’re good about charging your iPod regularly and just want to keep the mophie strapped on for emergency use, just flip the switch on the very bottom so the red icon is showing. This puts it in Standby Mode.)

With fairly regular use (though definitely not constant), the juice pack air kept my iPod charging for about three days, which is pretty great. After that, it was all on my iPod. I admit, I ended up charging it before it was fully drained—lest I find myself without my music!—but I’m guessing that, with my usage (roughly three hours per day) and both devices at full charge, I could easily go nine or ten days without plugging it in.

All that being said: I’m sold.

(mophie also offers these devices for iPod Touch 2G and the iPhone 3G, 3GS, and 4. Check out their site for similar products for older devices.)

mophie juice pack air for iPod Touch 2G, $59.95;

Joshua Pramis is an online associate editor and resident tech guru at Travel + Leisure.

Photo courtesy of mophie.