The Go charger works by either turning a crank or rolling it along a surface. The charger sells for 350 rupees, or about 48.35 yuan, and is about the size of a mobile phone.

The World Bank estimates that in India, more than 400 million people live without electricity and brownouts are common for everyone. So the companies have developed an injection molded recharger that works without electricity -- it can be hand-cranked or rolled to generate electricity for a mobile phone anywhere.

The device, called Go Charger, picked up a Plasticon award for innovation at the recent PlastIndia 2009 trade show in New Delhi.

“The penetration of mobile phones in rural areas has become really fast in the past one or two years, but the electricity penetration is not that great,” said Ankit Mehta, managing director of IdeaForge in Mumbai, which develops chargers.

India has between 250 million and 300 million mobile phone users, but handset maker Nokia Corp. thinks that figure could top 500 million by the end of 2010. Mobile phones outnumber land lines in the country because mobile networks are cheaper to build.

To make the mechanical charger work, a person either turns a crank or rolls the device along a surface like a wall or pant leg. About one minute of cranking or rolling is needed for three minutes of talk time or 30 minutes of standby.

The charger sells for 350 rupees, or about 48.35 yuan, and is about the size of a mobile phone.

Users can charge a phone while they are talking, noted Anand Palsodkar, lead design manager at Pune, India-based Elephant.

Previous mobile phone chargers, mostly developed in China, used cranks and were difficult to work with one hand, he said. Those chargers also had internal batteries, which Elephant wanted to avoid, he said.

“People want to make calls as they are recharging,” he said. “We thought, there has to be some alternative way to charge it.”

The charger was launched in October, and for now is targeting rural areas in India. But the companies see opportunities to push the Go Charger as a “green product” in other markets.

Elephant staffers said the project shows that products can be developed successfully for poor, rural communities in developing countries -- places where people may not think there is enough of a market.

“This [Plasticon] award shows that there is enough scope to develop products for the segment at the bottom of the pyramid,” said Ashish Deshpande, a founding director of Elephant.

Palsodkar said there are many Indian companies targeting that segment, whether in vehicles, financial services like microfinance institutions, or mobile phone service providers.

Incomes are growing, he said, and the diversity of people and cultures in those rural markets provide good opportunities for designers.

“In the bottom of the pyramid, there are various strata of people, different income levels. There is huge diversity,” he said. “This diversity poses a lot of challenges on design and offers a lot of opportunities for design.”

There are challenges. Products have to be rugged to handle India’s temperatures -- which range from freezing to 55° Celsius -- and rough treatment from things like jostling on crowded buses and trains. And products have to be affordable and flexible, Palsodkar added.

“Value for money in India is essential,” he said. “People would like to have choices, but they also look for value for money.”

For now, he said the Go Charger is available only in black and doesn’t use fancy graphics as a way to trim costs.

The charger -- which has an ABS body, nylon crank and thermoplastic elastomer grips on the side and wheel -- requires only molding and assembly, and no other processes.

“Cost becomes an underlying factor,” he said. “In terms of design, you would have to use minimum parts, minimum processes, and common parts or readily available parts.”

The design uses plastic gears on the inside. It turned out to be a challenge to find an Indian manufacturer that was affordable and could meet quality requirements, Palsodkar said.

The company ended up delaying the project about six months, he said.

“There are people who will do tooling and molding that are affordable, but when you go to those sectors, you have those challenges,” Palsodkar said. “You can’t go to someone [in India] working for Mercedes.”