Mophie Juice Pack Air review

Mophie's Juice Pack Air combines an external battery with a protective hard shell case for the iPhone 3G or 3GS.

Its shiny black plastic case is reassuringly robust, and the iPhone slots into it easily, but firmly. With the Juice Pack fitted, the iPhone feels only very slightly heavier than in its unsheathed state, and the only noticeable addition to its footprint is along the bottom edge, where about half a centimetre is added to its length.

The battery in the Juice Pack Air also adds about a centimetre to the depth of the iPhone but that's a small price to pay for the benefits.

As a case, the Juice Pack Air is good, but not great. It's solid and robust, but offers no protection for the iPhone's screen, and we found removing the iPhone from the case problematic - in part due to the sheen on its plastic surface. However, it's the additional battery life that's of most interest here. Mophie claims that a fully-charged Juice Pack Air will give an additional 270 hours of standby time, nine hours of talk time on 3G, and 20 or 27 hours of audio, depending on whether you have an iPhone 3GS or 3G.

The Juice Pack is charged by means of a mini-USB socket that's also connected to the Dock connector inside the case. So with an iPhone in situ, you can charge it using the supplied USB cable. Alternatively, the same method can charge the Juice Pack's battery. There's a battery indicator on the rear of the case, making it easy to see how much charge it has. It's also certified by Apple and carries the 'Works with iPhone' badge, meaning you should have no worries about it damaging your phone.

We were impressed. The slim, robust case was barely noticeable after a while, and we quickly got used to using it. And the additional battery life it afforded us was genuinely appreciated. Our only concern is the lack of protection for the screen. We'd be reluctant to use any iPhone case that didn't offer some method for preventing scratches or cracks. However, if you're less concerned about that, the Juice Pack Air is well worth considering.