Portable Solar Powered Outlet

Intro: 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?  

STEP 1: Prep the Panels

This step is pretty easy but tedious.  

Remove the top of the garden lights and expose the screws.  

Unscrew the "lid" and set aside (don't throw it away).  You should see some hardware (battery connectors, wires, LED, battery).

Remove all the unneeded hardware - this would the battery, the wires for the battery (make sure you don't pull out the panel wiring), battery connector and LED.

STEP 2: Solder Longer Wires

Now that you have the panels cleaned out, it's time to solder.

Add a length of wire to each of the wires coming from the panel.  This will make connecting them later on very easy.

After you solder the wires, feed them through the hole in the cap and screw it down.

STEP 3: Test, Test, Test

Test out your panels using a multimeter.  

In full sun I was getting about 2.5 volts per panel unit.

STEP 4: Construct the Box

Time to make your box. 

My box was 12" high, 12" wide and 18" long.  

I used 35 panels and each was approximately 1.75" in diameter.  If your panels are the same size this is probably the smallest you can go and leave space between each panel.  

You'll need to figure out what size you want your box to be and it's going to be based on how much room your panels will take up.

STEP 5: Drill the Lid

Time to make the lid.  

I used one of the panels as a guide to draw the circles to be drilled out.

I used a 1 3/4" boring drill (I think that's what they're called) and it ended up being slightly too small so I Dremeled out the holes to make them a little bigger.  

I suggest starting the drilling process on the middle of the lid so you aren't pressing down on the middle when there is very little material left on the outsides of the lid - you may break your lid if you try that.

STEP 6: Install Panels

After drilling/painting/finishing the lid, put the solar panels into the holes you've drilled.

Because I got a little happy with the Dremel and made some holes a little too big I used a little gorilla glue to help hold the panels in.

(After using this in the sun, the glue got soft and I had some panels fall through when I was driving up a very bumpy road  - I would recommend using copious amounts of glue or finding some other way of ensuring they stay in... I'm still working on repairing mine, any suggestions for an adhesive that won't go soft in the sun would be appreciated).

STEP 7: Wire in Series, Then Wire the Series in Parallel

Lay out a towel or something soft and turn your lid over so the panels are down and the wiring is up.

I had my panels in five rows of seven and that's how I wired them.  I had five series of seven (resulting in between 16-18 volts per series) which I then wired in parallel.  (I wired red to black, red to black, red to black all the way down.  Then I connected the ends (one end was my red end and one was my black end) together and ran them out to the charge controller.)

I used electrical tape to cover the solder points but heat shrink would have been nicer, I just didn't want to buy anything else for this project, so tape was it.

STEP 8: Add Boxes to Your Box

Back to the box. 

I cut out a hole and put an outlet box in the hole and wired the outlet (with some help from the electrical guys at Home Depot and my father-in-law) with the cut end from an extension cord.  The male end of the extension cord was going to be plugged into the inverter.

On the opposite wall I cut a hole for a light switch to be able to turn the inverter on/off without opening the box.

STEP 9: Mount the Inverter

Put the inverter into the box and bracket it down.  The brackets I used were originally intended for plumbing but were pliable and could be cut with kitchen scissors (thanks, Honey!) to the appropriate length.

I really screwed the thing down as I don't want it to move.  It's pretty solid in there.

I left the switch that is physically on the inverter in the "on" position so the light switch could do turn it on/off.

STEP 10: Mount the Charge Controller

I put the charge controller on the side of the box as the bottom would fill up pretty good when I put the battery in there.

Again, I used the plumbing bracketing and really screwed it down.

STEP 11: Mount the Battery

Now that the charge controller, inverter and panels are all installed and ready to go, it's time to put the battery in.  I bracketed it down as well so it couldn't move.

Please note - I did not connect anything to the battery yet until everything else was ready to go so I didn't have powered wires as I was trying to hook things up.  

I'll explain (and show) the connections in the next step.

STEP 12: Hook It All Up

Time to hook everything together.  

This is the order in which I did everything:

1) Panels connected to charge controller.
2) Outlet connected to inverter.
3) Inverter wired to a light switch I installed so I didn't have to open the box to turn it on.
4) Charge controller wired to battery.
5) Battery wired to lightswitch/inverter.
6) You're done!

STEP 13: Finishing Touches

Now that everything is wired you're basically done.

I put hinges on the lid so it would hinge up and I also put an adjustable support so the lid could be opened at various angles for more direct sun exposure.  

I also drilled two small holes in each side to run some rope through for handles.  


Enjoy!

Comments

[Chillplays_YT]

How many watts does this produce?

[rxpc]

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.

[Robert Powell]

Walmart now sells lights with real glass cover and a nice bright led with a 1100 mAh Ni-Cd AA battery for $1!

[MacOSJoey]

About how much does this thing weigh with all those components? Also, how many amps can your system produce off of solar? You specified that you can run an 80 watt device for three hours, or 240 watt-hours. After that, how long does it take to recharge the battery fully off of solar?

Great instructable!

[JasonE]

Thank you!

Let me preface my response by saying I am not an electrician and am VERY new to electricity. Most of what I know (okay, nearly all of it) I learned as I was putting this together.

The battery/inverter combo is what actually produces the power that you use when you plug something in. The inverter is a 410 continuous watt and 800 peak wattage (it will turn off when it gets that high). The battery is a 12V 26AH battery. So, to my understanding, the inverter is capable of delivering more power than the battery is able to produce for one hour (12*26=312 watts). Of course if you were to run a higher powered machine you could get the power you needed but for shorter periods (assuming the inverter could handle it).

I don't know how long it would take to re-charge. I am not sure how to figure that out. I know that each series produces 16-18 volts in full sun and that the charge controller I have connected will allow for 14 volts to the battery (if I understood that right). So the panels have more than enough voltage to meet that. The charge controller also has a 7amp max input so it's not more than that.

I also understand that there are different types of charge controllers and some of the more expensive ones work in cycles to charge the battery. I don't think this one does that as it was among the less expensive ones I could find.

As far as the weight - most of it is in the battery which is about 20 pounds. I'd say it weighs probably no more than 25 pounds. It's not something to take backpacking but toss it (gently) in the back of a truck and it will work well for you on camping trips, etc.

I hope that's helpful...?

[MacOSJoey]

Yes. Your response definetly cleared a few issues. This could be EXTREMELY useful during a power outage or on a camping trip! Very good idea and nice work with the solar panels. I never would have thought of wiring them together like that. Very handy instructable! Good luck in the green tech contest! I can't vote for yours because I'm in it too, my instructable on solar is here: https://www.instructables.com/id/Home-built-solar-power-system/

Thanks and good luck!

[JasonE]

Thanks! Same to you!

I looked over your project and my first thought was "Holy cow!" You really did a lot of work and obviously understand this type of thing more than I do. It looks really cool! I'm just getting started with all of it but it is fascinating.


(A side note -- a reading of the official rules of the contest told me that the votes people receive are for entertainment value only and don't determine the winner. The winner will be determined by a panel of judges. Good luck to you all the same!)

[ZanderH]

i think it would be a good idea to add a charger as well as the solar panels.

[katabillups]

Thank YOUUUUU! brilliant!!!

[servant74]

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).

[Sahm83]

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]

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:

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

[madmedix]

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 :-)

[guffix]

Nice. But why didn't you use a 10w solar panel? Same size, Less work to do, more ampere....

[nathconley]

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!

[joeledmund]

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

[ktshoema]

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.

[ktshoema]

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!

[BrownDogGadgets]

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!)

[clarksonchief]

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