Offgrid solution: Using discarded smartphone batteries to light up rural homes


Researchers at Kyung Hee University in Seoul, Korea, have come up with a model for recycling unspent lithium ion batteries from discarded smartphones into energy storage units for solar-powered LED lamps, writes.

With an average consumer lifetime of just around three years, discarded smartphones are generating massive amounts of e-waste and also squandering potentially useful lithium ion batteries, which can last for about five years, according to the science and technology news website.

The plan by Kyung Hee University researchers would not only cut down on environmental but also provide storage for rural communities.

Boucar Diouf, a professor in the Department of Information Display at the university outlined the recycling and repurposing program this week in the Journal of Renewable and Sustainable Energy.

The program would consist of five steps: battery collection, testing and selection, system manufacturing, commercialization and installation.

Diouf adds that the candle and kerosene lamps used by homes in many rural communities are harmful, inefficient and more expensive than a small solar home lighting system.

"Using the battery of mobile phones in small solar home systems becomes obvious in order to make access to electricity easier to those who live without."

A standard lithium ion phone battery of 1,000 milliamp-hour capacity can power a 1 W LED lamp for about three hours, or a 0.5 W lamp — bright enough for reading and writing — for about six hours. When wired to a small solar panel, this maintenance-free system can last for about three years.

The researchers have also built a 12-volt system out of three mobile phone batteries of 3,100 millliamp-hour capacity each, with a 5 W LED lamp and a small solar panel, for less than $25. These systems can light up a room for about five hours each day and last for around three years without any maintenance, according to

Diouf plans to start pilot projects in Senegal and sub-Saharan African countries within the next year.