Don’t bother with solar backpacks

Spare battery is more reliable

Fortune magazine are going off-grid crazy as it slowly dawns on them that you don’t have to live in a yurt to be off-grid. Their busy, important readers are off-grid too, each time they step out of the cocoon of their air-conditioned offices.

Their latest is a reader review of solar powered briefcases. The negative results also apply to all the solar powered bags we’ve seen so far.

Can a sun-powered briefcase keep you connected off the grid, asked Forbes. A reader writes: “Like many entrepreneurs, I spend most waking hours surgically attached to my phone, a T-Mobile Dash that I use mainly for voice calls and calendar tracking. I’m lost if it runs out of juice, so I was excited when Forbes asked me to test solar-powered bags

–small pieces of luggage with external solar panels that can charge small devices such as PDAs and cellphones. (None of the bags I tried generate enough juice to charge a laptop.) I tested all three bags by running my Dash until the battery was dead and then timing a full solar charge outside, taking note of sun and cloud conditions during each test.

VOLTAIC’S MESSENGER, $229 – 4-HOUR CHARGE

This laptop carrying case comes in black, green, orange, and silver. It ships with an internal battery that charged my Dash in a bit less than four hours. But the Voltaic lost major points when it fried my phone as I tried to bypass the battery and charge directly from the panels, which, it turns out, deliver higher voltage than the battery. Note to Voltaic: Please idiot-proof future releases of this bag. The Voltaic was also finicky about sun–it stopped charging in both full sunlight and moderate shade. (voltaicsystems.com)

ECLIPSE SOLAR GEAR’S “FUSION” MESSENGER BAG, $170 6-HOUR CHARGE

This dull green bag was apparently designed to look used even when new. The low-profile solar panel gives it the lowest geek factor of all three bags. Sadly, the Eclipse also turned in the weakest performance: Six hours of full sun gave my Dash only about a 30% charge, after which I had to suspend the test. Also, the outlet is awkwardly placed so that the cord impedes fishing trips into the bag’s interior. (eclipsesolargear.com)

REWARE’S JUICE BAG 1.0, $175 3-HOUR CHARGE

This solar backpack comes in green, gray, red, and camouflage. The soft solar panel is mounted in a flap that folds over the entire pack. I liked this bag’s clean, functional design: The charging pocket is located on top of the pack, separate from the main compartment, so you don’t have to worry about the bag’s contents damaging your equipment. In direct sunshine a full charge took slightly less than three hours. (rewarestore.com)

BOTTOM LINE

I liked the Juice Bag’s smart design and fast-ish charging. But unless you have to work for days in remote (and very sunny) spots, you’re better off just taking extra batteries.”