If you own a HYmini, you can attach it to your arm or bike to take advantage of speed.

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Using Wind-turbine Chargers

The first thing you do when you get a HYmini is plug it in.

It takes about 4 hours to fully charge the HYmini battery using a wall outlet. The battery charges your cell phone, MP3 player or digital camera via the built-in USB port (or an adapter connected to the USB port). Once that full charge from the wall outlet is used up, that's when you go green.

The design of the HYmini is sporty, with a propeller just a few inches across and attachments to secure the unit either to your arm or to your bike. Wind is intended only as a top-off -- you can hold the unit in the wind or create your own wind on a bike or skis. The turbine generates up to 1 watt of power in 9 mph to 40 mph winds (15-64 kph); above 40 mph, it cuts off so the blades don't spin too fast. If your cell phone dies, find yourself 20 minutes of 19 mph (30 kph) winds and you'll get yourself another four minutes of talk time -- more than enough to call a friend to come pick you up after a wreck. Or, you could use those 20 minutes to power up 40 minutes of music or 20 digital photos.

For another 0.7 watts of power, you can attach up to four mini solar panels and hold the unit in direct sunlight.

The Orange Wind Charger is intended for camping-type applications, not high-speed ones. The 12-inch (30-centimeter) propeller separates from the tower for packing, and you reassemble the unit upon setting up camp, usually atop a tent where the blades will have good wind exposure. Once the turbine fully charges the control-box battery, you can unplug the box and take it anywhere to charge your phone on the go.

With the Orange's half-watt power output, with the blades spinning in steady 12-mph (19-kph) winds, it takes up to 2 hours accumulate a full charge for a phone [source: GotWind].

Which brings us to the drawback of the wind-powered charger: Sometimes, there's no wind. This is more of an issue for the Orange turbine, which is intended to stand in place and catch environmental winds. For the HYmini, with its solar add-ons, generating power can be more of a sure thing -- in daytime on a cloudless day, at least.

Still, in an emergency, a wind-power charger is probably better than no charger at all. And at about $50 for the HYmini (no word yet on how much the Orange will cost if it hits the market), it could be worth it to bring one along and hope for a little help from nature.

For more information on wind-turbine chargers and related topics, look over the links on the next page.