日々更新mobilerA8（Yahoo!ニュースを毎日ウォッチ）

ラップトップコンピューターのバッテリーは何時間充電なしで動くかがポイント。
４時間が２時間になってしまったらもう寿命。
しかし、夜の明かりを採る為になら、まだまだ使えるという話。
実際、プリウスなどの電気自動車の電池は、車では使えなくなったら、家庭に使うということは考えられている。
BBCより。
Old laptop batteries could power slums, IBM says
http://www.bbc.co.uk/news/technology-30345221Old laptop batteries still have enough life in them to power homes in slums, researchers have said.

An IBM study analysed a sample of discarded batteries and found 70% had enough power to keep an LED light on more than four hours a day for a year.

Researchers said using discarded batteries is cheaper than existing power options, and also helps deal with the mounting e-waste problem.

The concept was trialled in the Indian city of Bangalore this year.

The adapted power packs are expected to prove popular with street vendors, who are not on the electric grid, as well as poor families living in slums.

The research, which comes from IBM's India-based research team, will be discussed at a conference in San Jose, California, according to Technology Review from the Massachusetts Institute of Technology.

Cheap
The IBM team created what they called an UrJar - a device that uses lithium-ion cells from the old batteries to power low-energy DC devices, such as a light.•••