iPhone 3G/3GS Battery Cases

Test 01

We plugged the full battery pack into a dead iPhone 3GS and left it to charge with the phone on, but the display off. The battery percentage reading was taken from the iPhone as soon as the battery case was empty. The Energizer AP1500, despite being good on paper, performed poorly.

Test 02

We plugged a dead battery pack and dead iPhone into a 500mA USB port on our Mac and timed how long it took for both to charge fully. Don’t stand around watching that process—it takes forever, though we were impressed by the Energizer’s and Mili’s times and, to a slightly lesser extent, the Mophie’s.

Test 03

With the pack and iPhone 3GS charged, we left the guided tour of Unreal’s Epic Citadel running with sound muted, and timed how much extra time we got with the battery compared to the iPhone on its own. As you can see, none got us quite up to two extra hours.

Test 04 Design and Features

You will notice that the Logic3 and Dexim leather cases are virtually identical, the only significant differences being the type of leather coating and the fact that the Dexim has a velcro clasp while the Logic3 has a magnet. We preferred the Logic3. But both these cases are bulkier than the Mili and Mophie ones.

The Mili’s clip-on design (which didn’t work with the iPhone 4) grips the 3G/3GS much better, and it also leaves the iPhone’s side-mounted buttons more accessible. The Mophie looks similar to the Mili, but the top is a separate slide-on piece.

The Mili, Energizer, and Mophie cases all have a strip of lights to show you the remaining charge level, and we like the Mophie’s best because the button is easier to press than the button on the Mili. The Logic3 and Dexim battery cases only have a status light that doesn’t show you how much juice they still have left in the tank.

All five have switches so that you can decide when to use the juice in the pack, although the only way to cut off power with the Mili is to remove the phone.

And the Winner is… Mili Power Spring

In a close contest, the convenience of speedy charging is worth the extra cash

We agonized long and hard about this one. Let’s first explain why we didn’t go for the Energizer case. It’s got an expensive list price, although you can find it for around $20 on Amazon, a real steal. But then if you’re investing in a battery pack, why get one that delivered so much less extra use time compared to the others?

So our attention turns to those others. In terms of how much charge they gave our iPhone and the additional use time they provided, there’s nothing really to choose between them. If we were interested purely in these two things, the Logic3 case would be a good bet, and we preferred its magnet clasp to the Dexim’s velcro. We like Logic3’s flip-case style despite the extra bulk, and its price tag is relatively reasonable (logic3.com gives prices in British pounds but will ship to the U.S.). But even with this, we can’t help feeling you’d be better off shelling out another $15 or so for the Mili, and here’s why. Granted, you don’t get any additional capacity or video time at the top-end of the price scale, but the Mili and Mophie products have three distinct advantages. First, there’s the charge level indicator, which we find incredibly useful, and the fact that they’re much lighter. But more importantly, look at those charge times! They’re both significantly less than the Logic3 and Dexim cases. And we like that, because if you’ve only got a short time to get your phone charged before you go out, speed matters and these guys deliver.

While some of the minutiae on the Mophie are better-implemented (the On/Off switch and the charge level button, for example), the Mili’s quicker charge time, coupled with the handier one-piece design and the way the iPhone’s buttons were easier to press with the case on, are what swung us in its favor.