XP2000Watching the power icon on your cell phone shrink down to nothing is no fun in the middle of a busy business day. Unless you have time to babysit your phone next to an AC outlet as it charges, you may have to reintroduce yourself to a communications device from another era: A pay phone.

Energizer, known for its battery products, hopes to fill the power void with its new Energi To Go battery pack products. For example, the Energi To Go XP2000 ($40) comes with a lightweight rechargeable battery pack, AC and auto power adapters, a flexible cord and a selection of power tips for the most popular cell phones, digital music players and other electronic devices like portable video games and wireless headsets. The battery pack has a standard 5-volt USB port like the ones found on laptop and desktop computers. Thus the unit can also charge most small devices for which you already have USB charging cables.

According to Energizer, the Energi To Go XP2000 (www.energizer.com <http://www.energizer.com/> ) can provide up to 12 hours of extra talk time for a cell phone. Aside from its AC and auto chargers, the battery pack can be also be recharged by connecting it to a powered USB port on a desktop or laptop computer.

The unit comes with a useful warranty: If the package, which comes with six power tips, didn’t come with the right tip for your cell phone or other device, Energizer will provide the correct one at no cost. In addition, users are entitled to two free tips a year for the life of the charger—a nice extra that comes in handy if you change phones.