Instructables
Picture of Portable Solar Powered Outlet
In this Instructable I will attempt to explain and show how I created my portable solar powered outlet.  

I've been able to continuously power an 80 watt device for approximately three hours without interruption and it could have gone much longer, as well as run an electric drill under load with no hesitation or slowing.  This is one powerful machine!

Remember as you construct your device that Volts x Amps = Watts.

There are a couple things to note before proceeding.  

1) This is my first Instructable, I hope I get it right.
2) I am not an electrician or a handyman.  I'm just an average Joe who used resources available to me and figured out something cool.  This Instructable involves wiring.  If you are not comfortable doing it or if you don't know what you're doing, learn before doing and don't blame me if you zap yourself.


What you'll need:
1) Battery (I used a 12V 26AH battery that I ordered off the internet for about $65)
2) Inverter (I used a 410 continuous watt inverter that I bought at Wal-Mart for about $35)
3) Charge Controller (I bought one off the internet for about $18)
4) Solar Panels (I used the garden lights that I bought from Wal-Mart for $0.97 each)
5) Electrical wire
6) Soldering Iron and solder
7) Wire strippers
8) Something to bracket everything down
9) "Normal tools" (needlenosed pliers, screwdrivers, stapler, drill, etc.)
10) Dremel tool or sandpaper
11) Multimeter

Ready?  
 
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servant745 months ago

For an adhesive, try some silicon caulk. It never gets 'hard', but it does hold and sticks to just about everything. For color sake, I would use black on the outside, and if you want something different, clear or white on the inside. It does a really good job of holding light items tightly and in a waterproof manner. It is also available at your nearest big box home center or hardware store inexpensively.

I have been toying with the idea. Current small charge controllers are in the $10 to $18 range on Amazon (May 2014). If you find them on sale, the 'solar panels' at Harbor Freight are very cost effective also (for the charge they can give over a given amount of time). Even 'commercial' panels can be found on the 'net' if you want to make a bigger unit (or instructables/etc on DIY Solar Panels aren't hard to make either).

A friend lives off the grid in the desert of west Texas using a DIY system very similar (but he uses lead acid, as he is stationary and for the volt/amp ratings used car & truck batteries are REALLY cheap and work well if they aren't shorted internally.

He even uses them for 'battery welding' metal, as well as power for computers, fans, lights. His are in a couple of 'solar sheds' he has built, (roof goes almost to the ground on one side, and slopes up at the angle the sun at the winter solstice). At the 'bottom' of these shed roofs, he collects the water from rain an pumps it into some large tanks. (drinking water he brings from 'town' in a barrel regularly - about 10 miles away). He is lots of fun to visit, but for a city boy, it would be a rough change in life style (for me anyway).

Sahm8311 months ago
I have been searching for (nonexistent) solar powered water heater for my chicken coop. This idea sounds like it could really help me out. I think I might give it a try being as I don't like the idea of running an extension cord across my yard. (The only other option being as my coop is mobile as I don't leave it in one place for a long time so waste build up is minimal). Do you have an idea as to how this would hold up if left on in colder weather?
webgiant Sahm838 months ago

Solar panels convert very little of the sun's energy into electricity. While top grade commercial solar cells have a 22% conversion rate, the amorphous solar cells in garden lights probably are in the 10%-15% conversion rates. As such, you would not be producing enough power with this solar project to heat water for any useful length of time. You would be much better off looking into the many solar water heater projects on Instructables which heat the water directly in a copper or black tube, since with those projects all of the sun's heat is saved directly into the water with very small conversion losses. If a portion of the coop needed to be in shade, the solar water heater could double as a shading awning over part of the coop.

Something like this project, reduced in scale and propped up at an angle would do the trick:

http://www.instructables.com/id/Solar-powered-Preheater-for-Tankless-Water-Heater/

madmedix1 year ago
I use removable caulking such as "Draft Stop". Comes in a tube, resists the highs and lows well (-20c). The trick is to use a fair size bead (I use 1/4") so you've got something to grab onto when you need to rip it off; The big bonus is that should a cell fail, this caulking can be cleanly pulled right off ( from a reasonably smooth surface) and allow you to install another...with more caulk of course :-)
guffix1 year ago
Nice. But why didn't you use a 10w solar panel? Same size, Less work to do, more ampere....
nathconley1 year ago
This was a really great idea, i made a project somewhat like this and i just used a super glue from like homedepot or lowes, it was pretty cheap and it held together beautifully when i went offroading with my buddies in california!
rxpc1 year ago
Nice idea, ....I hope it's working ouit for you. From what I've seen using the solar panels from LED garden lights like you got from Walmart really cheap is that they only produce between 35ma to 75ma.

You can check the mah rating on the batteries that come with them. I've seen quite a few of them, and most are 350mah, meaning a 10% charge of 35ma. The largest mah battery I've seen in a solar garden light was 700mah, the solar panel from that garden light put out around 75ma in good sun.
joeledmund1 year ago
what did you do with the 35 2/3 AA batterys i would have use them to make a bigger battery series - parallel to increase volts and mAH
ktshoema1 year ago
I have also done some estimating and I think each one of those solar panels is around 200mA's. Since you did series parallel. 7 in series = 1400mA= 1.4 A. At a ~13v system that would make your system ~18 Watt system.

You also said that you had a 26AH 12vbattery (~312Watt).

I would estimate (and i might be thinking wrong) 1.4 Amps into 26 amps would mean it would need about 19 hours of straight light/charging to fully charge your battery. That is not including the loss in the charging process.

I have concluded that I think you just have a fancy batter pack that you would be better off charging off an 120v outlet if you knew you were going to need it. That is not saying you can not run things off the solar. Just saying that you cant count on the panels doing a very good job of charging the battery (but I might be wrong).

1 solar panel should be able to run 2 LED's (100mA each). That would give you about 14 LED's! 1 USB powered device also pulls about 500mA. so you might be able to charge around 3 cell phones at once just off of the panels.

I looked into charging a laptop. In AC they would draw less than 500 mA, but in low V DC, it takes 3-4 Amps!
Your inverter will allow for higher Voltage but it will reduce the amperage that your panels/ battery are supplying. You are better off trying to run all DC devices than going from DC to AC and back to DC (like phone chargers and laptop chargers).

With your battery, you will be able to run a lot more, but again, don't count on your panels to recharge it.

I hope this helps. You got me looking into doing something similar to your design and those where the things I came up with.

Hopefully someone else can confirm my thought!

Hope it helps and sorry for being wordy! Great work though.

ktshoema1 year ago
would have been cool to keep all of the LED's and rig them into your box. different switches to control a different set of lights!
Awesome job. I love using cheap garden lights for projects.

The only thing I wonder about is how much current they put out. I've generally found that little garden lights don't put out very much current in general. For $40 you could easily buy a 5 Watt panel from someone or buy some "b" grade surplus cells and make your own panel.

Just an idea. I love "up cycling" stuff, especially stuff found at the dollar store. (Buy a dollar store radio and two garden lights. Hack them together and make yourself a solar radio!)
I don't comment often enough but to you I will give the Kudo's. Great job I've been planning about the same thing for a while just didn't have the time to lay it all out, yours gave me several ideas that will be put to great use. Thanks
JasonE (author)  clarksonchief2 years ago
I'm glad it was helpful! Good luck on your project!
DoctorDv2 years ago
This is awesome! Do you know the total cost? Also, how long does it take to charge the battery? Thanks!

-Doctordv

JasonE (author)  DoctorDv2 years ago
Thanks!

As for cost, I'm going to assume that you already have all the necessary tools and wiring.

Battery: $65
Inverter: $35
Panels $0.97 x 35 = $35 (I'll round up)
Charge Controller: $18
Electrical boxes/covers: $5 (I'm guessing here, but it's close)

Total: $158 (ish) before tax/shipping

As for how long to charge -- that's a good question that I simply don't have an answer for. The easiest (and most accurate) answer would be: it depends. It depends on how much you drain it and how much sun light you expose to your panels. All my readings I mentioned in the instructable were taken in full sun light. Obviously if you have passing clouds or intermittent sun light your input will vary. Also the charge controller has a lot to do with it. If you use one with differing cycles then it will typically charge to a certain percent and then trickle charge after that. Mine isn't that fancy.

I hope that's helpful.
Can you give the source of the charge controller, or was it a one time deal? Peace
JasonE (author)  onemoroni12 years ago
I got the charge controller off Amazon.com -- it's a Sunforce 7 Amp Charge Controller. Manufacturer number 60012. I paid about $18 for it.

If you search on Amazon for that I bet it wouldn't be difficult to find.

Good luck!
Thanks, I was curious as to the wattage. I was looking at Harbor Freight they have a 100 watt controller for $25 and a 200 watt inverter for $20. Seems the big dollar item is the battery, but this is much cheaper than the manufactured 80 watt systems costing around $900.
JasonE (author)  onemoroni12 years ago
I don't know if my controller stated its wattage. It can be figured out, though, by Volts x Amps. My controller is a 7 amp controller, so then the watts would be determined by how many volts you are sending to it. My controller has a volt limit of 13-14 volts (depending).

The wattage from the controller is less important than the wattage from the inverter because you can just leave the box in the sun to re-charge but you want a higher wattage to power whatever you want to power.

My inverter is a 410 watt continuous inverter so it will provide 410 watts of constant power. My battery can deliver 300+ watts for one hour before it is drained and in need of recharging so my inverter is perfect for my battery. You'll need to determine how big you want your components and select them appropriately. For example, I considered purchasing a 1,600 watt inverter but that would be too big for my battery in the sense that it would provide a lot of power but the battery wouldn't be able to keep up for long -- does that make sense?

And yes, the battery is the big dollar item.

A manufactured 80 watt system for $900?! This set-up, while needing to be re-charged from tie to time, provides far more than 80 watts and is far cheaper.
Using the formula, P=I x E, 7 amps X 14 volts = 98 watts. I may consider a little higher wattage from Harbor Freight. They have a 400 continues/800 peak inverter for $30. I really want to make this when I get the bucks for the battery. I have your instructable book marked for when I do. I'm thinking of reworking the box, but may keep the wood design. Thanks for the feedback. Peace
Schmidty162 years ago
ok dude this the thing ive been waiting for for like a very long time love it but u could even make it mor portable did u know that but very good instructable
You could put wheels on it...
i think it would still be a little big to carry around
JasonE (author)  Schmidty162 years ago
It's definitely not something you'd take backpacking but it fits nicely in a car trunk or the back of a pickup truck. The weight is almost all battery and it's not uncomfortable to carry or pick up.

See pic:
DSC00668.JPG
ok looks nice
Cool.
JasonE (author)  Computothought2 years ago
Thanks! It was a lot of fun to make.
conmac8632 years ago
Very nice project. Really good instrucable too.
I think on those solar panels you can can actually break the plastic away and just leave the actual glass solar panel and wires.
That could cut down on the size you needed. You could just drill small holes for the wire and then glue the panel directly on the top of the box sealing the wire holes.. So just basically a box covered with square solar panels.
But again really nice project and I will be using this for a box I want to build.
Thanks.
JasonE (author)  conmac8632 years ago
Thanks!

Breaking the plastic was actually my original plan and I did it to ten of them. The problem I had was the glue was different on some of them and trying to pry the panel away from the plastic and pull the wires back through ended up with some of the wires being pulled completely off the panel. I thought, "well, I can just solder them back on" but then I realized what a pain in the butt that would end up being and I had the epiphany to just leave them in the plastic as I wouldn't have the wiring problem (plus it was not easy to take the panel off the plastic).

I ended up leaving them plastic on, which did result in it taking up more space but in my mind was preferable to the alternative of having to re-wire some (a lot) of them and take the time to get them off the plastic.

Along with that plan I was thinking of putting a plexiglass cover over the panels to protect them but when I decided to leave them in the plastic I figured they didn't need the additional protection.

If you do end up doing just the squares, please let me know how it worked out for you.

Best to you!
l8nite2 years ago
thats a really great idea and a nicely done step by step "ible"
JasonE (author)  l8nite2 years ago
Thank you!
onemoroni12 years ago
You did a great job of creating cheap solar power for the common man. I assume the output is 110 volts. Nice application of the cheap solar lawn lights. I didn't think they could have any other application as to their low quality, but now you have cheep easily replaceable solar units. You asked about glue, I'm partial to "Shoe Goo". It's inexpensive and I use it for almost everything including covering the steel toes of my work boots. Good adhesion and always a little flexible. Peace
JasonE (author)  onemoroni12 years ago
A second response re: cheap lights.

I saved the stems (they'd make great conduits or piping for another project), the LED's and the rechargeable batteries.

Seriously, for a buck I got a solar panel, an LED, a rechargeable battery and a small pipe. Talk about a good deal!
JasonE (author)  onemoroni12 years ago
Thank you!

I'll look into the shoe goo too.
Nick705872 years ago
I would recommend liquid nails, or a two part adhesive. Or maybe put another board on the back with holes just big enough for the wires and a thinner board on the front with holes maybe 3/16" smaller then the panel diameters to sandwich them in place.

Very nice instructable for your first one. I was thinking about DIY'ing a solar panel for the roof of my shed to charge my cordless drill batteries and run my landscape lights. Thanks for the helpful info.
JasonE (author)  Nick705872 years ago
Thank you for your kind words.

You know, I thought about another board but time was of the essence and frankly I was tired of the project by the end and just wanted it done. Now that everything is soldered I don't really want to go un-solder it all. I'll look at the liquid nails too.

When you say "two part adhesive" I'm assuming you mean something that you mix the epoxy? That's what I used and it locked the panels in good... until the off-road adventure coupled with hot sun happened. :)
cowboynwh2 years ago
What is the model number of the charge controller? What website did you oder it from?
JasonE (author)  cowboynwh2 years ago
I ordered it from Amazon.com and it looks like I paid about $18 for it.

It is a Sunforce 7 Amp Charge Controller. Manufacturer number 60012.

I hope that helps you.
Dr.Bill2 years ago
A couple of tight fitting 'O' Rings around each cell one top one bottom half would keep them in the holes. Or a bit of plumbers tape with screws under each cell as brackets or even small 'L' brackets screwed to the underside would keep them in place. Hot Glue not so much...
JasonE (author)  Dr.Bill2 years ago
That's not a bad idea. I'll think about it - thanks!

I didn't anticipate (obviously) what the hot sun would do to my glue. I thought, "Hey, Gorilla Glue is tough. I'm sure it can handle anything."

Oops.
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