Public payphone redux: You may soon be able to drop a coin and charge your mobile


Aditya Aamir is irritated and angry. His smartphone is dead for the third time in seven hours; its battery is draining power like a leaking faucet: 10 am “battery full”; noon “battery low”! Twice, he has bought replacements, but the problem continues.

The 20-year-old is not alone. Cellphone batteries have a nasty habit of running out of power just when you need them most, which is almost always.

To get around the problem, five students of Moradabad Institute of Technology (MIT) have invented what they call a coin-cellphone charger.

The idea

Akash Verma is one of the five. When he was in the final year of Btech in 2016, his professor had given the class a project to come up with something innovative. Five of them — Akash Verma, Osheen, Swati Singh, Ekta Gupta and Arshad Khan — got together and came up with the idea of a solar-powered cellphone charger. They took six months to develop a running model.

“We got the idea from the coin PCO, public payphones that was in use until a few years ago,” says Akash. The team financed the project with their own money; they spent Rs 3,500 to make the first model.

“We got the idea from the coin PCO, public payphones that was in use until a few years ago” — Akash Verma, one of the developers  

“We started work in January 2016. The coin-cellphone charger was ready for trial by July 2016,” says Osheen. “It could fully charge five mobile phones more than 10 times a day.”

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Solar power is at the core of the invention. The coin-cellphone charger comprises a five-volt battery and a solar panel. A light dependent resistor (LDR) sensor attached to the solar panel helps convert solar energy into electric signal output. The nine-inch long, six-inch wide solar-powered charger can be installed indoors or outdoors. If the sky is overcast and it’s raining, the battery can be reinforced with regular electrical power.

“The machine was tested at the MIT Campus. Later, we did a presentation for then Uttar Pradesh minister Ram Moorti Verma,” says Osheen.

The coin concept

The idea is based on the coin payphone. Drop a coin in the slot in the solar panel of the charger and power your mobile’s battery. These chargers can be installed at bus terminals, railway stations, malls and shops, on the road and at intersections. India has the second largest number of smartphones in the world with more than 220 million users, says The Hindu.

Solar power is at the core of the invention. The coin-cellphone charger comprises a five-volt battery and a solar panel  

The charger has slots to feed coins and five charging pins to charge mobiles. The machine can be adjusted to take in Rs 5, Rs 10 and Re 1 coins. Osheen says in half an hour it can charge a mobile upto 40% its capacity.

(L-R) Swati Singh, Ekta Gupta, Manas Singhal (professor), Akash Verma, Osheen and Arshad Khan. The five students got together and came up with the idea of a solar-powered cellphone charger

“We made the machine for rural India. About 25%-30% charge is enough to make calls so people can charge their phone according to their need. Vendors can earn upto Rs 100 every hour if they charge Rs 20 an hour for five mobiles.” The vendor can also decide his / her own rates.

The charger has slots to feed coins and five charging pins to charge mobiles. The machine can be adjusted to take in Rs 5, Rs 10 and Re 1 coins  

The timer on the machine can be set by the coin-cellphone charger operator, says Akash. “Charging time for five charging pins can be individually and separately set. Five mobiles powered simultaneously will not affect charging capacity,” he says.

The news of the invention and its purpose was published in the International Journal of Recent and Innovation Trends in Computing and Communication. Osheen says they will patent their invention.

For now, Akash and Osheen have been placed in a Pune-based networking company, Ekta is studying for an MBA while Arshad Khan and Swati Singh are eyeing the IAS.


Lead visual: Angela Anthony Pereira The ‘Tech Meets Bharat’ series brings to you stories on how technology is impacting and changing lives in hinterland India. ​Sagar Rastogi is a Mordadabad-based journalist and ​Saurabh Sharma is a Lucknow-based journalist​. Both are members​ of 101Reporters.com, a pan-India network of grassroots reporters.