Discarded laptop batteries could form the basis of home lighting power supplies for poor communities in developing countries. According to David Talbot in MIT Technology Review, researchers at IBM Research India in Bangalore reported at the Symposium on Computing for Development (DEV 2014) held last week that 70% of discarded batteries have sufficient “life” (W-hr capacity and usable number of charge/discharge cycles remaining before end-of-life) to power an LED four hours per day for a year.
In the paper presented at DEV 2014, Vikas Chandan and his coauthors (representing IBM Research India and Radio Studio India) note that 40% of the world’s population lacks access to a reliable electricity supply. Consequently, people often have to make use of kerosene lamps for illumination, which poses health and environmental risks. Lack of reliable electricity also leads to the proliferation of battery-powered devices in the developing world—adding to the proliferation in the developed world—which leads in turn to a surfeit of e-waste, including Li-ion batteries.
To address these problems, the researchers investigated laptop battery packs that had been discarded after being used for at least three years by a multinational IT company in India. They found the batteries had an average 64% residual capacity, corresponding to 50 W-hr, or enough to power an LED lamp, DC fan, and mobile phone charger for about four hours.
To make use of these batteries, the researchers developed UrJar, derived from the Hindi words for “energy box.” To build the UrJar, they take used batteries from the e-waste stream, disassemble them to extract usable Li-ion cells, reconnect the usable cells to build a refurbished battery pack, and build a box containing a charging circuit and other electronics necessary to power a lamp, fan, and mobile charger. Their 6-W off-the-grid charger, for example, is based on FSEZ1216 IC (now obsolete) from Fairchild Semiconductor. A variant of their design could employ direct solar charging.
The researchers report that they provided a prototype to a tea and cigarette vendor, who was very happy with the device after three months and had “no problem at all.” (In addition to being used at home during power outages, the device can be used by street vendors who have no grid connectivity at their places of business.) Two more prototypes were shared among four participants. Three out of these four were satisfied with the device and would be willing to spend INR 1,000 (about $16) for it if it came with a one-year warranty.
Talbot in MIT Technology Review reports that IBM is not planning to develop UrJar as a business but could offer the technology for free to poor countries.
Of course the UrJar cells will ultimately reach their end of life and re-enter the e-waste stream. Writing in the comments section of Talbot’s MIT Technology Review article, researcher Zainul Charbiwala said that for many materials “there is a superefficient ‘supply chain’ of segregation and recycling” in India. Batteries aren’t yet part of the recycling ecosystem, he says, but adds that a small deposit or incentive, like the deposit on a soda can in the U.S., might help a battery-recycling ecosystem emerge. He notes, however, that his team did not investigate this possibility.
See a related article on maintaining refrigeration in India to preserve milk despite power outages.
