70 percent - our #numberoftheweek

It's a surprising number: 70. Not because of the figure itself, but because of what it means when linked with computer batteries. At least 70 percent of discarded laptop and desktop computer batteries still have enough power to keep an LED light running for at least four hours per day for a whole year.

Researchers from IBM Research in Bangalore, India, found that the remaining power could be tremendous help to poorer countries in providing electricity storage. With the batteries being rechargeable, it could also be possible to combine them with solar panels.

The MIT Technology Review website quotes Vikas Chandan, a research scientist, who led the project as saying that: "the most costly component in these systems is often the battery. In this case, the most expensive part of your storage solution is coming from trash.”

The reseachers for the project opened discarded laptop battery packaging and extracted the cells, tested them, picked the good ones, and recombined them to turn them into refurbished battery packs. These packs were tested by Bangalore citizens.

In the United States alone, around 50 million laptop and desktop computers are discarded every year. Meanwhile, in India, around 400 million people lack grid-connected electricity.