The average ultraportable notebook gets barely more than 6 hours of endurance when running at 40 percent brightness. That’s not enough to get your favorite geek through a long plane ride or an active day running around the show floor at CES.
Most of the external batteries on the market can only charge USB-powered devices like phones and tablets. However, there are a couple of options that will also charge a laptop. The Veho Pebble Pro, which really saved my bacon during hurricane Sandy, costs just $70 and comes with a slew of tips for charging. Mac users will appreciate one of the Hyperjuice batteries, such as the $170 60Wh version that promises an additional 20 hours of endurance.