Carbon puts a portable solar charger on your wrist

Carbon is a wristwatch-like portable solar charger that gives you up to three hours of extra power for your gadgets on the go.

Wearable tech seems to be the hot new thing, and there are some pretty crazy ideas out there — but this one looks to be genuinely useful.

Called Carbon, and currently seeking Kickstarter funding, it looks a lot like a wristwatch — only instead of a watch face, it has a solar panel. It's an idea we think has some definite advantages over other portable chargers. The solar panel, worn on the wrist, means that you don't have to remember to charge it; and the wearable design means it's always to hand, so to speak.

Just because you don't have to charge it, though, that doesn't mean you can't: the device can also be charged via USB, and a full charge can give you an extra three hours of use (talk or web browsing, based on tests performed on the iPhone 4S and the Samsung Galaxy Exhibit, so your mileage may vary a little).

The device itself consists of the solar panel set in a metal silver or black case. On the side is a knob that looks like the crown of a wristwatch — this is actually a screw-in cap for the 2.5mm jack charging port. The cap keeps dust and liquid from getting inside. A button allows you to set the Carbon in charging mode, and an LED indicator lets you know when the device is ready to charge, and also charge levels when charging via USB.

The watch also comes with a variety of charging cables, to suit the needs of multiple devices: Apple Lightning and 30-pin; micro USB and regular USB, both male (for charging Carbon) and female.

Carbon is being offered as a reward for an early-bird Kickstarter pledge of US$95 with a black silicone strap (going up to US$115 when all early bird pledges are taken), or US$130 for the entire package, including brown leather and black silicone interchangeable straps and a protective case. Head over to the Carbon Kickstarter campaign for more info.