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
- 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