April 22, 2010 AT 10:24 am

EARTH DAY – Voltaic DIY Solar, how to solar charge an iPad #earthday

Pt 2841
Voltaic has a great DIY solar section and blog, check it out! Here’s a good post on solar charging an iPad…

We test-charged an iPad with our solar backpack and it worked, but with two caveats: 1) The iPad charges from a USB port like a phone, but its battery is 25 Watt hours (about 5x that of an iPhone), so charging the iPad will take about 5x as long. 2) You’ll need to put the iPad into sleep mode for it to charge.

This is not a bug in our charger, it is due to the size of the battery and the charge circuitry within the iPad. Since the iPad has such a large battery, it is designed to charge best off a wall charger or high-powered USB port found on a Mac and some other computers. If you plug it into a normal USB port on a PC, you’ll get 2.5 Watts instead of the 10 Watts or more you get from a high-powered USB port.

If you want to solar charge your iPad from one of our Backpacks, you should plan on plugging it into a full Voltaic battery at night or at a time time when you’re not planning to use the device. We are going to do more testing, but it took us an hour to get from 77% to 83% charge.

You might also want to carry a spare battery as it will take about 3 full Battery Pack V11s to fully charge the iPad.

The other option is to use our Generator battery, which outputs 2Amps / 10 Watts and will appear more like a wall outlet to the iPad, although we currently out of stock.

Update: A customer using our earlier Silver JetPack battery (14.4 Watt hours capacity) reports going from 38% full to 81% in three hours. He did put the iPad into sleep mode before charging.

Pt 2840

Celebrate Earth Day 2010 with Adafruit – we’ll have posts all day and night with fun power/earth/green related projects and we’re having a one-time only sale on solar panels! Get a 2W solar panel 6V, 330mA out for $20, today only!

Check out all the Circuit Playground Episodes! Our new kid’s show and subscribe!

Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground”Adafruit’s Apps!

Maker Business — Adafruit interviews Dan Rasure, Managing Partner TechShop 2.0

Wearables — Simulate tattoos

Electronics — Heatsinks aren’t enough!

Biohacking — Getting More from Home DNA Testing

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !

No Comments

No comments yet.

Sorry, the comment form is closed at this time.