Off the Grid, Part 3: How to jump-start a MacBook with foot power

It’s hump day! And so begins the third day of my off-grid blogging in observance of Earth Week here at DVICE. Translation: no wall sockets or municipal juice for me until Saturday.

Due to rain yesterday, I had to forgo plugging my laptop into the Solar PowerPac II, my big solar-rigged generator. Though the battery status lights indicate it’s at half capacity (thank you, sun-kissed Monday), I can’t risk sucking my main power source dry. Hear and see how a bit of aerobics can jump-start a laptop after the Continue jump…

Yesterday I mocked the weather forecast. Bad idea. By noon, a wave of clouds rolled into San Francisco and those “chances” of April showers became imminent. Losing charge time wasn’t part of my plan, so I opted to conserve the Solar PowerPac II. After a couple hours of working straight from my MacBook’s 55-watt battery, the computer puttered out late yesterday afternoon. Inevitable bummer. And unfortunately, we’ve got patchy clouds this a.m., and I’m just not convinced there’ll be enough sun to offset any charge-time from the generator (remember, I gotta make it to Friday).

Enter the FreeCharge, Weza’s $300 “portable energy source.” Translation: a 7-amp-hour lead-acid battery that powers up as you step down on a lever. Interesting factoid: Weza (pronounced Way-zah) derives from Swahili for “heart attack” …OK, it means “power,” but no joke, I can no longer deny I am one out-of-shape blogger.

Around 7:35 a.m., I plugged a 12V inverter into the Weza’s DC output (max output is advertised as 120 watts, though step-charging only generates between 25 and 40 watts) and connected the MacBook’s 60W adapter to the inverter. Now, I had assumed the Weza would be completely discharged out of the box. I must confess it did not; it registered half full. It was a wonderful surprise, but I concede this does put me in close proximity to the grid. Then again, keep in mind that even pocket-size solar chargers require or recommend a full wall-socket charge before first use. So I digress.

And Presto… the Mac adapter’s light powered on red. So far so good. After a few minutes of hot steppin', I tried powering up the MacBook: 1% battery! However, the screen started to bug out and the Mac’s battery status read "not charging." Conclusion: do not attempt to work on laptop while charging. So I shut down and continued cranking, leaving the laptop’s charge cord in place.

After 20 minutes of huffing and puffing, I wasn’t optimistic. I had no clue how much power would get lost in the inverter on its way to the computer. I left the Weza hooked up and took my dog for a walk. At 9:40 a.m., when I unplugged the computer and powered it up, I couldn’t believe it. The battery was back up to an astounding 52%!!! And after 15 minutes, it was down to 43%. How this might affect my battery long-term, I don’t know (if you do, please drop some knowledge in the comments… and yes, I backed up my hard drive last week just in case this somehow fries my Mac). Still, what I do know is this: I managed to squeeze in enough time to quickly whip up this post!

OK, I’m heading out for a little field trip. I don’t want to say too much, but check back in tomorrow for my attempt to deliver a few portable solar chargers to the masses.

Oh, and here’s a video of the Weza in action. The faster the stepping, the better the charge. When the noise gets high-pitched, my step input registered a 5 out of 6 according to the charger’s indicator lights. Tiring, but satisfying.

Previous Entries
Off the Grid, Part 1: Every watt counts
Off the Grid, Part 2: Do watched solar pots ever boil?