Lenmar makes all manner of rechargeable batteries, battery chargers and accessories for consumer electronics. It recently added these here Bat Paks to its lineup.
The Bat Paks are two-in-one universal battery packs that are compact and portable, functioning as a charger to recharge portable electronics in addition to being a full-on battery pack.
There are three models available for powering everything from cell phones to laptops. One is powered by 4 AAA batteries (included) delivering up to 14 hours of extended power for devices accepting 5V USB power such as cell phones, MP3 players, PDAs and even PSPs. The second is an ultra slim-line rechargeable Lithium-Ion cell providing up to 20 hours of portable back-up power for handheld devices. The third is a compact external laptop Lithium-Ion battery giving an extra 2-4 hours of portability for travelers. MSRPs range from $19.99 to $149.99.