Repurposing the OLPC Hand Cranks—Into Mobile Phone Chargers!

Whenever I’ve made a presentation or stood at a display about my team’s work in Haiti, at my university or elsewhere, for an audience of people who are not already working closely with OLPC XOs, I get a question to the effect of: “What happened to the hand cranks?” In fact, it’s almost become a mental game I play once the display or presentation starts: How long until we get the hand crank question?

Every beginning-of-semester, I have my students try them out. After about 5 minutes (max!) they’re done cranking. Usually it’s more like 2 min.

I found a humorous discussion thread on OLPCnews: “Trust me after 5 minutes you want to let someone else have the fun. After 10 minutes you will pay someone to crank it. 4 of us took turns and did the hour. The next day the 2 of us that are wimps couldn’t lift our cranking arm.”

So what to do with the excess ones we had? We decided to repurpose them into cell phone chargers, since that seemed like a more realistic use for them: phones need less charging/use less power, charge on 12 volts, sometimes you just need enough power to make a short call or send a text, and in today’s world, even out to the ends of the earth, where there’s no reception and no powering source, people still own mobile phones! Also, the teachers at the EFACAP school had asked whether they could use the solar system for charging phones, and we felt it was something valuable to add in to the system.

So we purchased some multi-use vehicle chargers with 3 12-volt sockets and a USB charger, (available for a few dollars each on Amazon). We cut the cords on both the chargers and the cranks, and soldered the red wires to the red wires, and the black to the black.

We tested them with our multimeters to make sure they worked, and then the students charged one of their ipods with it, since that was the only device we brought with us that charged with a usb cord. My own cell phone has such a cord, but I hadn’t brought it.

We also wired one of the multi-chargers directly in to the solar system and built a little shelf so that cell phones could be charged on the shelf.

We left the newly repurposed cell-phone charging cranks with the headmaster on our final day there, in December.

Update 4/25/12: I gave a talk yesterday about my team’s work in Haiti. Not even 5 minutes in, someone raises their hand to interrupt my talk with the question about the hand crank. Really!