Picture of Universal Solar Charger
This is a universal solar powered charger for those of you (myself included) with minimal electronic knowledge and even less money. You make it out of one of those cheap universal car adapters and you can still use it as such afterwords. You can even change the panel you use whenever you want!
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Step 1: Materials needed

Picture of Materials needed
Ever want to charge something like your cell phone, mp3 player or even your gameboy, but don't want to pay over $60 for those portable solar chargers? Well, this is the place to find out how to do it. The best thing about this charger, is that you don't have to permanently attach it to your panel allowing you to change panels whenever you want! This instructable cost me about $10 since I had most everything lying around, but if you bought everything new, it should run you about $20-$30.

First off, let's see exactly what you will need to get this project started.

1 - Solar panel (mine in the picture is a 5.5w panel. You can
get them at Canadian Tire for about $30 on sale
and you can even get them at Wal-Mart now for
about the same.)
1 - Universal DC (Can be bought at many places for about $10)
to DC Charger

1 - Quick Connect

Tools including solder, screwdrivers, soldering iron and shrink tubing if you want.
Might be a good idea to put a blocking diode inline between the charging device, in case you forget to unhook the charging device from th8is setup when there is no solar panel output, IE, when the sun isn't present or it's too cloudy to get (sufficient charging) output current from your panels. Otherwise, you risk draining your battery!
theo673 years ago
Are you sure about the positive, I thought that the centre terminal was a positve. Perhaps on your polarity revering model it was around the other way.
Best do verify with a cheap meter
Here in the US, a good place to get a 5w panel is harbor freight, or make your own by salvaging several dead old LED solar yard lights
GreenD5 years ago

Good find with that car jack charger, I wonder how easy those are to come by.

jimbowen5 years ago
Cheers mate works a treat !!! : )
It's hard to tell from the photograph (all I can make out are a few resistors) but it looks like that adapter does not provide any regulation. If it is unregulated ( and the panel definitely is) it would be unwise to plug expensive electronics into it! Is there at least a diode in the circuit to prevent the device discharging via the solar panel when the sun goes in?
that adapter does regulate the output voltage. It uses a lm317, which is a variable voltage regulator. The output voltage is set by 2 resistors. The switch on the adapter changes the resistor combination to give different output voltage values.
mettleramiel (author)  Patrick Pending7 years ago
Good point. I completly forgot to mention that. It shouldn't be a problem with most small electronics. The small amount of current that a 2 or 5 watt panel (the size that these are intended for) puts out makes it pretty hard to cause any real damage in a day or so of sun. I added to the end of the instructable to include this, though.
Try Power Monkey Explorer it functions as a solar charger and storage your charge for use at night
Myself7 years ago
A few quick comments: In step 2, it's pretty clear that the blue wire is negative, and black is positive. You're right that black is usually negative, but this appears to be an exception!

Also: You should really avoid those trailer-style quick connectors. They make it extremely easy to blow things up, since they change polarity when you change sides. What I mean is this:

Say you have a battery in a box, with a wire leading out of the box so you can charge it. On the wire you have a quick-connect, with a matching one on the solar panel. For this example, let's say that the battery's negative is on the exposed QC terminal, which mates with the solar panel's shrouded terminal. On the solar panel, then, positive is on the exposed terminal.

Not too bad, until you accidentally plug two batteries together. Now you have negative to positive and positive to negative, a dead circular short, which will melt your connectors, catch your wiring on fire, detonate your batteries, and ruin your reputation!

Consider a genderless connector like the AndersonAnderson Powerpole, which has become the standard in many DC-power applications for precisely this reason. The APP connector keeps its polarity when you change sides, so you can just plug all your batteries, chargers, solar panels, and loads together without worry. Positive is always positive, negative is always negative. You can probably find them at your local hobby store, since they're popular with R/C modelers, and any ham radio club will sing you their praises (and probably help you pick up some nice tooling for cheap).
redpill Myself6 years ago
Anderson power plugs are not the standard. Deans plugs are the way to go.
Myself redpill6 years ago
Dean's plugs are popular in R/C modeling, where gender-based connectors make sense, since you're either connecting a battery to a vehicle, or connecting a battery to a charger. But say you're connecting three solar panels, two batteries, a light, a fan, two radios, and a laptop charger. Which devices get which gender of connectors?

That's precisely why Anderson Powerpoles are popular in amateur radio and other environments where things aren't always as simple as in an R/C model. Just throw a few pairs of connectors on everything, and plug it together however you like. Positive is always positive and negative is always negative, and there's no need for gender. Deans and JST connectors are great in some applications, but Powerpoles (also called Sermos connectors by some modelers) are more appropriate on solar panels, batteries, and power distribution applications.

Anderson Powerpoles definitely are the standard in many applications. ARES/RACES have specified them as the official standard DC power connector for all their operations, and they're the de facto standard across all of amateur radio. For simple one-battery-one-device connections, the connector varies with the industry, but anywhere you find people doing complicated things with DC, you'll find Powerpoles.
redpill Myself6 years ago
I just like deans plugs. I actually use a male XLR plug on the each solar panel and a female panel mount connector on my battery bow that connects to my solar charger. They work nice because they lock and don't look half bad.
redpill redpill6 years ago
battery BOX*
the spring \ fuse is usually positive
mettleramiel (author)  Myself7 years ago
That's right, you can't always trust the colour of the wires, that's why I said to use a multimeter if you are not sure. On this particular model, however, it doesn't matter because there is a switch that allows you to choose the polarity you want on the side. The others that I made had those anderson connectors you mentioned.
The tip of the plug is always posative and the sides are always negative
maker127 years ago
i made a circuit i call a "cat,s bladder" it will help this out

sorry for the gross name!
whitish7 years ago
sweet I'm gonna do this with a Ipod car charger.