Power sources, batteries a challenge for One Laptop per Child
Margery Conner - October 10, 2007
The One Laptop per Child (OLPC) project, which seeks to provide $100 laptops to children in third-world countries, has had to overcome an almost overwhelming array of technical challenges, not the least of which is: How do you power a laptop in areas where there is no grid, no reliable source of regulated power?
The designers have come up with several options, both solar- and human-powered, made feasible by the fact that the XO laptop consumes far less power than conventional laptops: 2 watts nominal, which the organization claims is less than a tenth of today’s standard laptop.
It looks like the first available alternative energy source for the XO will be flexible thin-film solar panels from ECD Ovonics, rather than the more efficient but less rugged (and more expensive) silicon/crystalline-based solar panels. OLPC uses the phrase “virtually indestructible” when describing the panels.
It looks like the XO will ship with a hand-crank from Freeplay (shown here as a hand-crank flashlight.)
Potenco has designed a string-pull power source for the laptop, but as of now there’s no firm production date.
OLPC says the battery pack will be lithium ferro phosphate (LFP), which is pretty interesting. This is basically the same battery chemistry being explored so aggressively by GM for its highly anticipated plug-in hybrid electric vehicle (PHEV), the Chevy Volt. LFP battery packs have some real advantages over the lithium ion-cobalt-derivative chemistries now used in most laptops and consumer goods: The phosphate version is by nature non-flammable, which is a good characteristic for products going out into primitive surroundings and being used by children. Also, LFP batteries have a faster charge time and can last through many more charge-discharge cycles than lithium ion cobalt. However — and it’s a big however — they don’t have nearly the energy storage of lithium ion cobalt, which in the past has been a deal-breaker for their use in laptops, where the ability to power your laptop through at least a feature length movie on a cross-country flight has been a necessity. Hmmm, not so much for this project, though.