If you are constantly frustrated with your mobile phone battery dying, then Motorola may have the answer. Their new P790 portable charger lets you recharge your phone without AC power. Unfortunately though, it won't work with all mobile phones.

According to Motorola figures, the P790 holds two full charges for a mobile phone and 10 for Bluetooth headsets and other accessories. The P790 uses a standard mini-USB connector, so it will work with most Motorola phones, including the MOTOKRZR K1, RAZR V3i, RAZR V3x, PEBL, SLVR L7, ROKR E1 and RAZR V3. The P790 will also work with any phone or accessory that uses a mini-USB connection to charge.

Once the charger runs out, you can juice it back up using a regular mini-USB AC adapter; most new Motorola phones include this in the sales package. Conveniently, users can charge their phone and the P790 at the same time via an adapter lead. The P790 takes two hours to fully recharge.

Despite being such a basic device, the P790 is quite stylish. It has a black rubber finish and is compact, measuring just 51.4mm x 51.4mm x 23.7mm and weighing a mere 79g. A slide up button on the front of the unit both powers on and slides out the mini-USB connector.