How-To: Solar charge your SPOT Smart Watch (and an iPod)

If you own a Suunto SPOT Smart Watch you usually charge it via plugging it in to an outlet or with the included USB
charger (which in turn is plugged into your computer). We're going to show you how to make a pretty cheap and easy solar charger for your watch that doesn't touch any of the included cable(s) at all. And what we're going to cover will most likely apply to many other USB powered gadgets you have as well, so even if you don't have a Suunto N3 SPOT watch,
there's some good info here.

As an added bonus, we're going to give you a sneak peak at a solar powered charger for Apple's iPod. If you want to see that, just skip to the end.

Ingredients

??? Sunnto N3 SPOT Smart Watch

??? iSun Solar Panel

??? USB extender cable

We'll go over each one and where to get them in the next section.

Suunto SPOT Smart Watch

You'll need a Suunto N3 SPOT Smart Watch. You can usually score one
around the web for under $250 and service for the year can be as low as $59. SPOT watches can receive personalized content such as news, weather and stock updates, calendar appointment reminders from Outlook, Instant Messages from MSN,
sports, daily diversions, horoscopes and lottery information. They're not for everyone, but if you have one and use one you probably love it.

iSun Solar Panel

The iSun Solar Panel is a gadget that you'll use for all sorts of things besides this project, so we think it's worth the $69. The iSun is meant to use the sun's energy to recharge your gadgets, we've used our iSun over the last year for Pocket PCs, phones, GPS device, just about everything...and now we'll use it to connect up to a USB connector we're going to make.

Here are the specs on the iSun.

??? Rated output: 2.2 watts (145mA @ 12volts, 290mA @ 6volts)

??? Temperature Range: -40F to 176F (-40C to 80C)

??? Voc = 15.2 VDC (12V setting) or 7.6 VDC (6V setting)

??? Dimensions: 7.25" x 4.5" x 1.25" (184mm x 114mm x 32mm)

??? Weight: 11 oz (311 grams)

We got ours from ThinkGeek.

USB Extender Cable

The USB extender cable is just a cable we're going to hack apart to feed the power from the iSun Solar panel to the USB charger for the SPOT watch. A lot of the time you get these free with some type of purchase, but if you don't have one handy any computer store sells them or you can pick one up from a place like
X-Tremegeek.com for $1.75.

Cutting the Cord...

USB cables have 4 wires, 2 for data, one for power and a ground.

??? 5V / Red

??? D+ / Green

??? D – / White

??? Ground / Black

Using a Pocket Knife, or wire splicer cut the USB extender cord in half and expose the 4 wires on the female end (the side that will be plugged in to another USB cable).

We snipped back the green and white since we're not going to use those (the data ones) we're only interested in the power and ground (Red and Black).

Here comes the Sun

Now, put the red wire in to the + (positive) input on the solar panel and the black wire – in to the negative. Using electrical tape or whatever you want, affix the two cords together.

Plug the new USB cable we just made (with attached solar panel) to the Suunto USB charger. Here's the tough part, you might actually need to go outside to test the charger.

Plugging in the watch, to the new cable, which is plugged in to the solar charger will give the watch a pretty good trickle charge. On the solar panel, you can always test to see if the panel is getting enough light by pressing the yellow test button.

We let out SPOT Smart Watch drain to about 30% and after using the solar charge it fully charged in about 2 hours.

Other USB devices?

It's certainly possible this will work with other devices that can recharge via the USB port, we have a Game Boy USB
charger a Pocket PC Phone edition one and so far it's worked out fine.

And of course, since the iPod can be charged via USB now, that works too???but you can't charge it directly from the solar panel.

The Solar Charged iPod

Most iPods can now be used and charged via a FireWire connection or USB 2.0. So after we started charging our SPOT
watch we looked around and thought the iPod was the next logical gadget to get some sun juice. Unfortunately plugging in our solar panel to the USB cable for the iPod won't do anything other than "wake" it up for a second.

So what you need to actually do is use the solar panel to charge a series of batteries and those batteries will ultimately charge the iPod.

Since we're just starting this project here are a few pictures of where we are at now. Once we finish, we'll make this a How-To article as well... we are a little concerned that some people might fry their iPods so we're spending some extra time on this one to make sure we document and experiment on our own warranty voided stuff first.

Phillip Torrone can be reached via his personal site: http://www.flashenabled.com or
torrone@gmail.com