Make a Handheld Solar Power Supply

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Introduction: Make a Handheld Solar Power Supply

I wanted to take a solar path light and turn it into some sort of self charging portable battery pack.

With a little bit of work it was surprisingly simple.

You will need :

- Some solar path lights (get the ones that can be easily dis-assembled)
- Some small gauge wire
- An 'Altoids' tin
- A 1/4" mono audio connector
- A soldering iron and solder
- Patience
- A brain

(Yes, we could probably use some hot melt glue, and shrink tubing and other fancy things, but lets be honest here, we're hacking something into an Altoids tin, this isn't rocket science.)

NOW, about that 1/4" connector...

I got a lot of comments from people asking about the connector and how it worked. Well here's the deal. It's just a plug. It isn't connected to an audio device, the pack doesn't send audio. it is just a nice shiny plug that has a +ive and a -ive part to it.

Most people are used to power going down a usb outlet, or some fancy 9V plug, or just a couple of alligator clips. What I wanted was something that was solid, robust and easy to handle.

My battery pack powers the lights on my bike (in fact I have 2 of them) so I need a plug that should withstand the weather, you could use while wearing gloves, didn't break easily etc. The 1/4" plug is all of these while also being easy to clean and has a large contact area which better handles bumps and dirt. the FEMALE connectors are also excptionally easy to keep clean (try getting dirt out of a USB plug...).

Step 1: Get an Altoids Tin

These things are great, no screws required, and they keep your breath minty while you work.

Step 2: Re-wire Your Light

You will need to gut your solar light. Pull it all apart until all you have is the solar panel, circuit board and battery holder.

Also remove the batteries.

All the wires that are currently attached are not only too short, but they will also break off as soon as you move things around.

So, you need to take them all off and solder on new wires that are longer.

Step 3: Attach the Solar Panel

Did you already re-wire everything ? Well you should have read the whole instructable first.

You have to thread the wires for the solar panel through the lid of the tin first. Then you can play games with hot lead.

Put some tape (Gaff, electrical, whatever) down on on the lid to insulate the solar panel's contacts from the metal of the tin. Then glue the panel to the lid of the tin, I used double-sided tape for this.

Step 4: Attach the 1/4" Jack

These phone jacks are big and clunky, which not only makes them easy to work with, but also easy to keep clean. They can handle a lot more brute force than some fancy tiny connector that you are probably tempted to use.

Take one of these and solder it to the contacts that feed the LED on the circuit board. Thus we are tapping the power that runs the LED.

LEAVE THE LED ATTACHED ! you still want some sort of indicator that tells you if you have a charge or not.

Step 5: Get This Mess Back Into the Box

Carefully assemble everything into the tin.

- Drill a hole for the 1/4" jack. The metal is THIN, take care
- Also drill a small hole for the LED to poke through the side

- Line the tin with some more tape or you will probably get a short circuit from the 1/4" jack
- Cover any exposed contacts with tape for the same reason
- Don't wiggle the wires too much, they will probably break on you

Step 6: Make It All Neat and Tidy

I used some foam to keep things from moving around. This also helped hold the LED in place against the side of the tin.

Step 7: Finished

That's it, we're done.

Close the tin, and admire the finished product. Leave it in the sun for a while and make sure everything charges.

If you don't get a charge, you probably have a short somewhere. Take everything out of the tin and see if it still charges. it if does, you need more tape to separate metal from metal

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    102 Comments

    this is a really cool tutorial

    My only question is why keep the led? Wouldn't that take away from the charge and if you used a solar chip that has a built in daylight sensor would the process still be the same? I'm thinking of a light for the star for my grandma's nativity set at Christmas.

    i love all the feedback and criticism because that's what makes us think. but I have a question for you. could I use three to six solar panels and a three pack of rechargeable batteries like what come in those cheapy lights and then use this to power that same or a better led or do I need to use upgraded internals due to higher voltage/amperage

    Why in the HELL would you use THAT connector.... i mean come on.... this isn't a guitar.

    Oh please, does it really matter what kind of connector he chooses? What would you have him use? Screw terminals? Are you some kind of connector bigot?

    ooh screw terminals sound nice lmao

    Because it is BIG and easy to keep clean. I use this system in a place that gets VERY FINE corrosive dust everywhere. The female end isn't enclosed and this easy to blow air out of, and the male end has enough contact area to work around a few rust spots. Ask an audio engineer why they don't use USB for guitar or speaker cables.

    Surely because the usb connectors appeared years later than jacks

    ;)

    slchorne I love this tutorial. I do have a question. Be gentle because I know nothing when it comes to electricity. I wanna use this to charge my iPhone when I'm out and about because I often forget to charge it at night. Now the wall charger gives an output of 5 volts. Would the device you show in this tutorial be able to charge an iPhone? I don't care how fast it charges just as long as I have it for emergencies. Another question: the 1/4 audio cable have a red and white wire in it which one is positive and which one is neg. Thank you so much.

    OK!
    This was a nice idea.
     
    This can be used as a solar-powered battery charger.
    You can take out the batteries when they are charged and use them where you like.
    In that case you do not need a jack and plug.

    If, however, you want to use the package as a portable power pack to connect to some device (the author uses it on his bike for the bike lights), then you can add your own choice of male/female connector arrangements.

    I could not tell from the photos whether the batteries are arranged in a 2.4 volt series configuration or in a 1.2 volt parallel configuration.  I am guessing 2.4 volt configuration (1.2 volts nominal, per rechargeable battery).

    As the author has hinted, he leaves the details to the brain power of enthusiasts who are really interested in how some of these simple things work.

    cheers