It started as a simple idea.
In 1993, Trevor Baylis saw a television documentary about efforts to improve the health of rural Africans and how those efforts were being hampered by poor communications. Many rural areas didn't have electricity and batteries could cost a farmer a month's salary. So the British inventor decided to build a radio that wouldn't require either.
To power it, you crank it up.
With designer Andy Davey, who worked on the Sony Walkman, he fashioned his invention into a marketable product. The result: the BayGen Freeplay Radio, an oversized lunch box of a device with a crank on one end. Wind it up for 20 seconds, and users can listen to 30 minutes of AM, FM, and shortwave broadcasts.
Because it operates on a giant spring, much like a window shade, the unit can be rewound 10,000 times before becoming worn.
Since its launch in 1995, the radio has become a hit in Africa and won endorsements from South African President Nelson Mandela, England's Prince Charles, and the Red Cross. BayGen, based in South Africa, has sold tens of thousands, says Vaughan Wiles, president of BayGen USA, the US subsidiary based in Warwick, N.Y.
BayGen has found other audiences for its product outside Africa. Last June, the company began marketing the $100 Freeplay in the United States. Campers and adventurers who stray off the beaten path, for example, are eager to stay in touch.
"The first world countries have gotten excited" about the concept, Mr. Wiles says. "There are so many gadgets - from cellular phones to laptop computers - that are totally useless if the battery runs down.... What we're seeing here is the beginning of a new industry [based on] the principle of personal power generation."
The company plans to deliver two to three battery-free products a year for the next five years.
Its next two products, due by midsummer, will be an extra-large wind-up light and a smaller, stereo radio model. Each would cost about $65.