Solar Panel Lightweight Hack

Solar Panel Hacking Project

Several months ago fellow backpacking and blogger Roman (aka LightHiker) offered up a free solar panel charger on Twitter to anyone who wanted it, all they had to do was to cover the cost of shipping. I narrowly beat Hendrik Morkel to be the first person to respond via Twitter – Ha, Hendrik :-)

I reimbursed Roman for the shipping cost (gotta love Paypal) and received the charger a few days later. Since then the charger has sat in my office starring at me and gathering dust because it was far heavier than I had originally thought it would be, much more so than I was willing to carry in my pack as a luxury item that’s for sure. But beggars can’t be choosers and I’m very grateful to Roman for letting me have it.

For some reason, this morning I got the urge to take another look at the solar panel to see if I could “lighten” it. This is what the charger looked like when I got it. I’m guessing it was a product sample handed out by HP at a conference or convention that Roman attended. It is necessarily big 5.5 x 7 inches (140mm x 180mm) but all of the packaging around the panel was heavy and bulky. The whole thing weighed 8.5oz.

Solar Panel Hacking Project

The enclosure is made from what looks to be thick Cordura or ballistic nylon and stitched in place around the inner solar panel. After a minute or two of carefully slicing through the stitching with my trusty Spyderco, I was able to separate the solar panel from the casing.

Solar Panel Hacking Project

There was nothing holding the solar panel to the nylon casing other than the stitching around the outside. So once I had unpicked it the panel simply slid right out.

Solar Panel Hacking Project

It’s a pretty basic solar panel with a single purpose USB port hard-wired on the reverse. I was pleased to discover that the polycrystalline silicon solar cells were encased in a transparent epoxy resin material and not glass as I had feared. The panel is much more durable than I had thought.

After taking it out of the casing it weighs just 3.6oz. That’s almost half the weight of a Brunton Freedom solar charger (6.6oz), but obviously it isn’t as nicely packaged. I’m thinking of using some black Sugru silicone putty to cover over the USB port and afford it a little extra protection. Then I might also use a small bead of Sugru (probably orange colored) around the entire outer edge of the panel to protect it and make it a little less rough to handle. That would look pretty cool and it will add a few extra grams, but that’s fine.

Solar Panel Hacking Project

I had tried the solar panel with my iPhone4 when I first received it, only to be disappointed that it didn’t have enough juice/output to recharge it. In fact my iPhone4 doesn’t even acknowledge that it’s plugged into the charger. That was another reason why I hadn’t paid much attention to it in so long.

But after hacking it to pieces and ending up with such a lightweight panel I was curious to try it again. We’ve had 100+ degree weather in North Carolina for the past few days, so I wondered if the blazing sun might help give the panel a little extra boost necessary to charge up my Phone?

Nope! It didn’t make any difference. At this point I wasn’t even sure if it was working at all or if I had buggered it up? I had my Garmin watch nearby and plugged it in to the panel.

Solar Panel Hacking Project

Success! The panel worked perfectly and my Garmin started charging as indicated by the flashing battery icon on the watch face. I also checked my work BlackBerry and that charged successfully using the panel. I’m bummed that this particular panel doesn’t have enough output to power an iPhone4, but it’s still useful for some of my other electronic items.

I’m not yet sure if I’ll carry it with me when I go backpacking, not because of the weight, but because the only electronic device that I am likely to have with me is my iPhone, and this doesn’t work with it. But at less than 4oz (estimated weight after adding some Sugru), it’s still the lightest solar panel that I know of.

Do any of you use a portable solar charging device when you go backpacking? If so, what make and model do you use and what has your experience been with it?

Reader photo from Carrick:
Carrick has left some great comments below describing his MYOG solar project. He also sent me this photo which I thought I’d share. Thanks again Carrick. 

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  • I’m not sure it’s the current from the charger to the iPhone that’s the problem.  I’ve noticed not all chargers work with my iPod.  I’ve got a few 12v chargers only some will charge the iPod.  In fact, I believe one of the older iPod nano chargers wouldn’t work with the Touch.

    It really seems as though iXdevices are fickle.  After Googling a bit I found this: http://forums.macrumors.com/showthread.php?t=324214  There are a couple tricks to try for your situation.  Hope one works.

    • Ha, I was about to do the same but you beat me to it and saved me. Yes it seems that it may not be an output issue but more of a circuitry (deliberately by Apple) issue. Thanks for the link – would be great to get this lightweight option working. I’ll post an update if I make any progress. Thanks Ken.

      • Apparently, there is an additional requirement for newer iDevices.  A small voltage on the data lines are required.  A simple hack should get you going.  Here’s a quick explanation of what if needed: http://www.instructables.com/id/How-to-get-your-iPod-to-charge-with-your-homemade-/  A quick trip to Radio Shack and some basic soldering skills, and you’re in business.

        • Ken, congratulations! You have just earned your Brian’s Backpacking Blog “Expert Hacker” social badge :-)

          Thanks so much fr chasing this down. I tried the soft/hard reset button options in that previous link you provided but it didn’t work for me on my iPhone4. I’ll read through this and see what I need to do. Gotta love a little RadioShack + soldering! Thanks Ken.

  • I’m not sure it’s the current from the charger to the iPhone that’s the problem.  I’ve noticed not all chargers work with my iPod.  I’ve got a few 12v chargers only some will charge the iPod.  In fact, I believe one of the older iPod nano chargers wouldn’t work with the Touch.

    It really seems as though iXdevices are fickle.  After Googling a bit I found this: http://forums.macrumors.com/showthread.php?t=324214  There are a couple tricks to try for your situation.  Hope one works.

  • Carrick

    I made a USB Solar Panel to charge up my iPhone in the bush.  The iPhone requires more circuitry to connect to a basic charger, this is why some devices aren’t recognized.  I solved this problem by purchasing small iPhone chargers on eBay, and they charge up with the solar panel.  Here is a link to the device.

    http://www.ebay.ca/itm/External-Backup-Battery-iPhone-2G-3G-3GS-iPod-E190-/150642440085?pt=PDA_Accessories&hash=item2312fd3795#ht_3175wt_1141

    • That’s a good way to get around the problem, use the solar cells to charge a battery pack that in turn WILL charge the iPhone. Thanks for sharing.

      Coincidentally, the solar panel I am using is by a manufacturer called AnySolar. They are a large scale manufacturer of generic solar cell panels to third parties and based in Shenzen, China – where the ebay seller of the power packs is also located! Conspiracy anyone?

      • joy2b

        Chinese factories make lots of the basic electronics we use these days, particularly the iPhones and accessories.
        However, the recent move into undercutting solar manufacturers elsewhere is new.  US companies have had a history of producing ever more efficient solar panels, Chinese firms are focusing on mass producing common small cheap ones, and have gotten significant subsidies to encourage growth.  The subsidies probably won’t last forever.

        • All I would like to have is a lightweight solar charger that can charge a camera or my iPhone in a pinch. All of the iPhone compatible solar chargers that I’ve seen are either huge or ridiculously heavy. I don’t need it to be able to survive a fall off a cliff, I just want a thin, flexible solar panel (film?) that I can carry as a backup. Surely someone can see there’s a niche market just waiting for this?

  • Carrick

    I made a USB Solar Panel to charge up my iPhone in the bush.  The iPhone requires more circuitry to connect to a basic charger, this is why some devices aren’t recognized.  I solved this problem by purchasing small iPhone chargers on eBay, and they charge up with the solar panel.  Here is a link to the device.

    http://www.ebay.ca/itm/External-Backup-Battery-iPhone-2G-3G-3GS-iPod-E190-/150642440085?pt=PDA_Accessories&hash=item2312fd3795#ht_3175wt_1141

  • Ha, I was about to do the same but you beat me to it and saved me. Yes it seems that it may not be an output issue but more of a circuitry (deliberately by Apple) issue. Thanks for the link – would be great to get this lightweight option working. I’ll post an update if I make any progress. Thanks Ken.

  • That’s a good way to get around the problem, use the solar cells to charge a battery pack that in turn WILL charge the iPhone. Thanks for sharing.

    Coincidentally, the solar panel I am using is by a manufacturer called AnySolar. They are a large scale manufacturer of generic solar cell panels to third parties and based in Shenzen, China – where the ebay seller of the power packs is also located! Conspiracy anyone?

  • Carrick

    i bought three of these solar panels and glued them together with some pegs at the bottom to stick into the ground.  Gives you about half an amp of current. it charges up the battery pack and leaves the iPhone free to use.  Keep half a dozen charged up and you are good to go!  One note, i have purchased 5 of these battery packs and one refuses to charge an iDevice, i’m not sure why this is, but its a good idea to buy a few.

    • Carrick, thanks for the additional information. How did you connect the solar panels together electronically? Did they come with the ability to daisy-chain them like that? Good advice on the buy many comment, probably just a matter of quality control not being as good as more commercially available products – but that’s the price trade-off. It’s still a neat solution albeit a heavier one. Thanks!

      • Carric

        They came as a 5.5volt dc 4x6inch panel.  The hookup is a positive and negative solder terminal.  If you connect them in series, you increase the voltage, i hooked them up in parallel to get the same voltage, but increase the current up to about 500 milliamps.  If you need more current, hookup more panels. After hooking up the panels, add a USB female port with two connections. i super glued all the panels to two plastic pitons like a tent peg, this holds everything together and allows for a way to point it at the sun, its very lightweight

  • Carrick

    i bought three of these solar panels and glued them together with some pegs at the bottom to stick into the ground.  Gives you about half an amp of current. it charges up the battery pack and leaves the iPhone free to use.  Keep half a dozen charged up and you are good to go!  One note, i have purchased 5 of these battery packs and one refuses to charge an iDevice, i’m not sure why this is, but its a good idea to buy a few.

  • Apparently, there is an additional requirement for newer iDevices.  A small voltage on the data lines are required.  A simple hack should get you going.  Here’s a quick explanation of what if needed: http://www.instructables.com/id/How-to-get-your-iPod-to-charge-with-your-homemade-/  A quick trip to Radio Shack and some basic soldering skills, and you’re in business.

  • Carrick, thanks for the additional information. How did you connect the solar panels together electronically? Did they come with the ability to daisy-chain them like that? Good advice on the buy many comment, probably just a matter of quality control not being as good as more commercially available products – but that’s the price trade-off. It’s still a neat solution albeit a heavier one. Thanks!

  • Ken, congratulations! You have just earned your Brian’s Backpacking Blog “Expert Hacker” social badge :-)

    Thanks so much fr chasing this down. I tried the soft/hard reset button options in that previous link you provided but it didn’t work for me on my iPhone4. I’ll read through this and see what I need to do. Gotta love a little RadioShack + soldering! Thanks Ken.

  • JJ_Mathes

    ahhahahahaha…geeks!  

    it had to be said  :^D

  • JERMM

    ahhahahahaha…geeks!  

    it had to be said  :^D

  • Carric

    they came as a 5.5volt dc 4x6inch  panel.  the hookup is a positive and negative solder terminal.  If you connect them in series, you increase the voltage, i hooked them up in parallel to get the same voltage, but increase the current up to about 500 milliamps.  If you need more current, hookup more panels. After hooking up the panels, add a USB female port with two connections. i super glued all the panels to two plastic pitons like a tent peg, this holds everyhing together and allows for a way to point it at the sun, its very lightweight

  • Guilt as accused. But I’m a UL geek!

  • Pgeeks

    Hi Brian,
    I used a GoalZero Nomad 7 and used it on a 5 day backpacking trip.  It managed to keep my phone and camera charged up.  Awesome!  Like your hack!

  • Pgeeks

    Hi Brian,
    I used a GoalZero Nomad 7 and used it on a 5 day backpacking trip.  It managed to keep my phone and camera charged up.  Awesome!  Like your hack!

  • Okay, I’m going nuts with this. It is apparently beyond my DIY electronics capabilities. Anyone able or willing to help me work through making the modifications to this? There might be some free gear in it for you?

  • All I would like to have is a lightweight solar charger that can charge a camera or my iPhone in a pinch. All of the iPhone compatible solar chargers that I’ve seen are either huge or ridiculously heavy. I don’t need it to be able to survive a fall off a cliff, I just want a thin, flexible solar panel (film?) that I can carry as a backup. Surely someone can see there’s a niche market just waiting for this?

  • joy2b

    Chinese factories make lots of the basic electronics we use these days, particularly the iPhones and accessories.
    However, the recent move into undercutting solar manufacturers elsewhere is new.  US companies have had a history of producing ever more efficient solar panels, Chinese firms are focusing on mass producing common small cheap ones, and have gotten significant subsidies to encourage growth.  The subsidies probably won’t last forever.

  • Bb

    I have wired to of these panels together with a female usb plug and have enough power to charge my htc vision its running at 5v @ 750 ma. :-)

    • Nice! Do you take it with you backpacking or is this just a charger on-the-go?

  • Bb

    I have wired to of these panels together with a female usb plug and have enough power to charge my htc vision its running at 5v @ 750 ma. :-)

  • Nice! Do you take it with you backpacking or is this just a charger on-the-go?

  • Dave

    Ken is correct, you need to supply about 2 volts on each of the data lines to get the apple device to recognize the charging. The trick is coming up with the hack. 2 volts will tell the apple device how much current it should draw to charge the device. You dont want it to draw too much on a solar panel.

  • Dave

    Ken is correct, you need to supply about 2 volts on each of the data lines to get the apple device to recognize the charging. The trick is coming up with the hack. 2 volts will tell the apple device how much current it should draw to charge the device. You dont want it to draw too much on a solar panel.