Back in November, I pitted iPhone 4 charging cases from Dexim and Mophie against one another. They both held one extra phone charge, but because it was lighter and much better designed, Mophie's Juice Pack Air for iPhone 4 was the clear winner.

A new entrant from each blurs the lines. In this rematch, the Dexim DCA224 Super-Juiced Power Case for iPhone 4 challenges the Mophie Juice Pack Plus for iPhone 4.

Specs: Capacity: 2000mA' Input power: 5V DC, 1000mA' Output power: 5V DC, 500mAPrice: $69.90 Weight: 3.2 ouncesColor: White

With poor construction for a premium price, the awkwardly designed Dexim Supercharged Leather Power Case I tested in November wasn't up to snuff. In stark contrast, the Super-Juiced Power Case offers a much sleeker design of thick and glossy white plastic that decks out your iPhone 4 like a Storm Trooper.

The fit is snug, and the plastic sheath has a cutout for easy access to the iPhone's volume controls and silent-mode switch. About an inch down the back is a hinge that unfolds the top from the backing. It snaps into place to lock the iPhone after you've slid it into the case. This is a neat design that serves the Dexim case as a single unit. However, the high backing does make it trickier to release the iPhone when you're done using the case.

Dexim has also added a thin kickstand that handily turns the charging case into a stand. There's a Micro-USB charging port, a charging light, and indicator lights that communicate the level of the case's charge. Dexim's case is a vast improvement over the shoddy leather case we saw before. The indicator lights and "juicy" name are suspiciously similar to Mophie's Juice Pack line.

Mophie Juice Pack Plus for iPhone 4

Specs: Capacity: 2000mAh batteryPrice: $99.95 Weight: 2.9 ounces Color: Black' Magenta, Yellow, Cyan to come

In terms of design, Mophie's latest Juice Pack is little changed from its predecessor. However, it feels slimmer and thinner in the hand than does its Dexim rival. It's made of rubberized sidings and a soft-touch material on the back cover. Its two pieces--one that covers the back and sides, one that slides down on top--still fit the phone tightly.

Instead of leaving the volume control unit open as Dexim does in its Super-Juiced case, Mophie opts to place raised volume and power buttons on top of the case body. Pushing those buttons depresses the iPhone's buttons underneath. Mophie's design continues to offer a Micro-USB charging port, power indicator lights, and the charge button.

Though Mophie's product claims to add greater power than Dexim's does, the recharging differences seemed negligible on our iPhone 4. Mophie's Juice Pack Plus may be slightly lighter and visibly sleeker than Dexim's DCA224 Super-Juiced Power Case, but it also costs about $30 more. We did find it a bit tougher to retrieve the iPhone from the Dexim, but the case earns points for its one-piece, hinged snap design and convenient kickstand.

Mophie loyalists still won't go wrong with the tried-and-true Juice Pack Plus, but new charging case owners should do just fine with Dexim's offering.