Instructables

Turn a playing card into a solar charger for AA batteries

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I own loads of rechargeable NiMH AA and AAA batteries, but most always seem to be dead when I need them.  So, I wanted a cheap and fast way to make battery chargers that I can keep on my desk, so that I could have an armada of charged batteries at all times.  I didn't want to take up more outlets and have more wire spaghetti with plug-in chargers, so I settled on a solar charger.  I'm in the solar business so I had stacks of small pieces of raw lasercut PV silicon cells (solettes) laying around, and I first made a simple battery charger with a few business cards as a backing.  Then I found that playing cards were a more stable backing -- and besides, they looked neat.

This instructable details my efforts to make a simple solar battery charger made out of a playing card, some solettes, some magnets and super glue -- if anyone has ideas on how to make this simpler and more effective, please let me know in the comments.

No soldering is required for this project.  It should take about 10-15 minutes.

First, check out this video.  There are two playing-card solar projects detailed in here -- one for a AA charger, and another for an arduino charge card (described in more detail here:  http://www.instructables.com/id/Solar-powered-arduino-on-the-back-of-a-playing-car/ )

 


p.s.  Where can you get the small bits of solar cells -- the solettes -- needed for these Instructables?  Well, it's a pain right now.  You can track these puppies down from suppliers in China, but they aren't easy to pin down:  http://manilamantis.wordpress.com/2012/04/25/the-dark-side-2/ 

So, to make this easier, my buddies and I are launching a Kickstarter campaign (Aug 15 - Sept 14) for all your solar DIY needs:  http://www.kickstarter.com/projects/alex9000/the-solar-pocket-factory-an-invention-adventure   Bangorang!

 
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sniffrumble2 months ago

For sure. You can just slice the tape down the length to get the right width for this project.

For sure. You can just slice the tape down the length to get the right width for this project.

sheepbars4 months ago

hi i'm back, i was also wondering if i could use a solar panel instead of those solutes! i couldn't find any! it has wires with it that has + and - polarities. I'm doing this as a science fair project and was wondering if my ill-equipped self could still pull this off.

cheshirecorn5 months ago

Thats fascinating...

For sure. You can just slice the tape down the length to get the right width for this project.

clawsgoal5 months ago

For sure. You can just slice the tape down the length to get the right width for this project.

chimplost7 months ago

For sure. You can just slice the tape down the length to get the right width for this project.

steveazhocar8 months ago
Hey i was wondering if I could use about 1/2 of a cm copper tape? i have over 15 ft. of it and i was wondering if i could use somehow.
regaltaxlaw8 months ago
For sure. You can just slice the tape down the length to get the right width for this project.
sfrayne (author)  gamebadly10 months ago
For sure. You can just slice the tape down the length to get the right width for this project.
sfrayne (author)  keithentwhistle1 year ago
Yup, for sure. You can just put the shorter pieces of tape at both ends of the card.
Yes, you definitely could just use a straight-up already-assembled solar panel.
JensonBut1 year ago
Love this! Will try it out myself! Very smart and practical!
hi i'm back, i was also wondering if i could use a solar panel instead of those solutes! i couldn't find any! it has wires with it that has + and - polarities. I'm doing this as a science fair project and was wondering if my ill-equipped self could still pull this off.
sfrayne (author)  TheSciencebro1 year ago
Yes, you definitely could just use a straight-up already-assembled solar panel. That said, we've made some solettes available in a kit here:

http://solarpocketpages.com/kits/

Good luck!
Hey i was wondering if I could use about 1/2 of a cm copper tape? i have over 15 ft. of it and i was wondering if i could use somehow. i need this project dow almost now! plz answer soon!
Great Instructable! I just received my solettes and I want to adapt your idea to make a cell phone charger. The question I have is the use of your dummy or your "false" solette. How does it bring the top surface connections to a solette underbelly? Do you flip the last solette upside down? If not, why wouldn't you just make the copper tape longer on both sides so as not to waste any solette?

Cheers, and thanks!

Alastair
sfrayne (author)  misobrilliant1 year ago
Hi Alastair,

Thanks! Re: why use the false solette -- using the superglue technique to connect solettes works decently well after a bit of practice, but using it to connect solettes to coppertape is flaky. So, instead of trying to mount the (-) copper tape section to the top of the last solette, I found it easier and more reliable to just do all solette-to-copper tape mountings from the bottoms of the solettes, particularly connecting the bottom silver ink bus bars to the copper tape. This then requires a "false solette" -- no flipping necessary though.

That all said -- you could solder the solettes together with a pre-tinned wire called 'stringing', instead of doing the superglue solderless technique -- and then the false solette isn't really necessary.
Cirdan2 years ago
I had a feeling you were a Beirut fan. Not sure what gave it away.
Excellent instructable...I'm looking forward to trying this myself. Thank you for making these solettes available to us through the Kickstarter campaign, as well!
sfrayne (author)  Cirdan2 years ago
Who's not a Beirut fan?
Cirdan sfrayne2 years ago
Everyone in a 50-mile radius of me, save for my wife. :\
bobwojo2 years ago
I liked your idea of using magnets as part of the battery connector.

I have small 1/4" magnets with a Nickel plating that is conductive. Using a low temperature solder (170 degree F) I soldered wires to the magnets,

Now I have magnetic connectors that stick right to the battery.
bobwojo bobwojo2 years ago
Here are photo's, Note that the positive contact on a AA battery is small and not very flat so use very flexible wire so the magnet will stick better and not fall off.
photo2.JPGphoto1.JPG
sfrayne (author)  bobwojo2 years ago
Zing! That's sweet.
sfrayne (author)  bobwojo2 years ago
Zing! Awesome! I found magnets to be the easiest way to make these battery chargers, but also an easy way to connect clips to raw solettes for quick experimentation.

So, you have a photo?
Josh1001002 years ago
What is the size of the solar power does anybody know?
Ok now im hooked !

Excellent instructable and thanks so much for the extra inspiration BUT !!!

Theres no way for us (John-Q-Public, Joe-Bloggs, etc) to CHEAPLY buy these 'Solettes' that are used to make this - they are not even sold on ebay !!!!

AAAAARRRRRRRGGGGGGHHHHH !! !! !! !! !! !! !!

How do we obtain such things if we dont know anyone in the solar-business like yourself ?!?!?!?

Any help would be greatly-appreciated & many thanks in advance !!
I have been buying them at the dollar tree. I get a solar panel,nicad battery led light bulb,diode,battery compartment and switch. But you can just twist off the top of the solar nightlight and all the work is done for you. You would have a hard time buiding this for under a dollar.
thats just Awesome !! many many thanks for the advice, i am most-grateful !
This ebay seller has loads of them for sale in a variety of sizes. http://www.ebay.com/itm/52x19mm-solar-cell-for-DIY-5w-solar-panel-untabbed-poly-solar-cells-/320907099098?pt=LH_DefaultDomain_0&var=&hash=item4ab78dbbda
MAJOR-Thanks !!!

i had been looking for these but so very many months ago that i gave up the pursuit in the end until now, a great many thanks for opening up these doors for me and im very grateful !!

also rated your 'ible 5 stars when i wrote my 1st comment and now another 5 !

thanks again !!!

;-)
ecodad2 years ago
What are the specs on the (optional) LED and Schottky diode shown in the video? Is there a trick to super gluing those to make a solid contact or do you use solder?

p.s. awesome project on Kickstarter
http://www.kickstarter.com/projects/alex9000/the-solar-pocket-factory-an-invention-adventure
kostya2 years ago
Looks great! Solette means a little sun, doesn't it? I wonder what is the amperage of those solettes in the video. Thanks for sharing.
sfrayne (author)  kostya2 years ago
Thanks! Each solette in the video puts out a short circuit current of around 125mA, with a max power point current (Im) in that ballpark as well (around 100-110mA). The shingling technique of stringing the solettes together blocks some of the output from each solette, so if you are getting 80-100mA delivered to your battery, that's right on. (this is also just right for trickle charging a 2000mA NiMH battery safely, even in max sun).
Thanks a lot for the info !
kostya sfrayne2 years ago
Thank you for the informative response. I'm looking forward to your upcoming projects.
I would love to buy Solettes, where can I buy them?
Solettes really aren't that hard to come by...if you search Ebay for solar pieces you get a tons of results. They tend to run only $6 for 40 pieces.
sfrayne (author)  cesar harada2 years ago
Get yer solettes here! http://www.kickstarter.com/projects/alex9000/the-solar-pocket-factory-an-invention-adventure

p.s. More Solar Pocket instructables coming in a few days....stay tuned.
sfrayne (author)  cesar harada2 years ago
Hi -- since solettes are pretty hard to come by , me and a few other folks are launching a solette-laden Kickstarter on Aug 15 -- I'll send a reply once it's up and running.

But for now, you can search on eBay for laser cut or laser scored monocrystalline (or polycrystalline) cells and find a few options. Like this:http://goo.gl/C25he
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