One Laptop per Child Laptop Power November 18

One Laptop per Child Laptop Power November 18, 2008 ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Challenges Supplying power can be a large and difficult challenge in a deployment. Even in areas with a power grid Lack of an established grid increased the difficulty significantly No recipe solutions. Each site is unique ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

How Much Power? 2 Primary modes of laptop operation Charging battery Not charging Charging battery Max draw of 21 Watts Closer to 26 W w. power factor correction Not charging Less than 1 Watt in sleep mode Average of 4 – 7 Watts while running w. peaks up to 9 W ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

How Much Time to Charge ? Fastest with the Laptop off: All power used to charge battery 1 hour 46 Minutes Laptop on: Excess power used to charge battery About 2 and half hours ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Individual solar panels Assuming maximum output (full sun) With the laptop off 5 W charges laptop in 5 hours 15 minutes 7 W charges laptop in 3 hours 45 minutes 10 W charges laptop in 2 hours 40 minutes ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Alternative Power Sources Individual Solar 10 Watt solar panels Only for smallest schools Centralized Solar High initial cost Large solar panel arrays and charge ctlrs. Some battery storage required Inverters to minimize distribution costs ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Alternative Power Sources Crank Still needs 2 hours of cranking. Not viable with existing XO laptop Weza Approx 30 Watt output 7 Ah Lead Acid battery Will charge 2 laptop batteries in 2 hrs. Grass Roots Cow power Water, Wind, Pedal, Treadle ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Multi-Battery Charger Charges 15 batteries in 2 hours 300 Watt AC 120 Watt DC option (10 – 28 Volt input) 8 Batteries in 2 hours Direct connection to 2 x 60 W solar blanket(s) Available in February ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Power Management Available today: Hardware ready for suspend/resume Current stable builds have support for sleep on lid close or button About 4 hours of battery life during normal use 14 -16 hours of battery life in sleep mode New “Extreme” power savings mode + additional power savings in sleep for nonmesh. (40+ hours of life in sleep) ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.

Deployment Planning Deployment Location Information needed How many schools, how many kids, and how many kids per school ? How many school off power grid ? How many hours of usage daily ? What is the climate and geography of deployment areas ? What natural resources are available ? ONE LAPTOP PER CHILD This works are licensed under a Creative Commons Attribution 2. 5 License.