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This is my first instructable covering a project I completed earlier this year. I have a shed which I use as a workshop as well as somewhere where I can train on my bicycle (on a 'Turbo Trainer') and as a general storage area. Although it's close to the house, there is no mains power available and having enough of resorting to using a touch every time I went into the shed in the winter evenings, I decided to have a go at installing a low voltage LED lighting system which could be run from a 12v battery that is charged from a solar panel.

Step 1: Design

I Googled and Googled.... I Googled a lot before I went any further. I had no knowledge of how to put one of these together and so it took a few days before I felt I'd learnt enough to know what I was doing. For those of you who are unfamiliar with the components of a solar charging system, it goes something like this:

You can hook a solar panel straight up to a battery and charge it.... however this all goes very badly when the battery is fully charged and you will actually damage the battery if you push anymore current into it. To prevent this you use a Solar Charge Controller, a device which sits between the solar panel and the battery. This unit is able to regulate the flow of current to the battery and therefore prevent overcharging and also prevents the load from draining the battery too far which also causes damage. There are two main types of controller; PWM and the MPPT Controller. (Thanks for the correction Malkaris)

The first, PWM (Pulse Width Modulation) is better suited to low power applications (< 170W) however it is not capable of dealing with any over voltage generated by the solar array. In comparison, the MPPT (Maximum Power Point Tracking) charge controller is far better at optimising the output from the solar array and can deal with the solar array generating excess voltage which can be harnessed and used to improve charging efficiency by 20%-25% (under the right conditions). PWM has been around a lot longer than the MPPT technology and as a result is generally cheaper and are available in a greater selection of sizes and models.

With all that in mind, I opted for the PWM model and set about buying the other components I needed.

Parts List

MPPT Controller: eSky Intellegent LCD 30A - £20.00

Solar Panel: 100w Pollycrystalline PV Panel - £70.00

Battery: 12v 35Ah Leisure Battery - £50.00

LED Strip: 5m 12v 5050 LED Strip - £12

Switch: 2 Gang Outdoor Switch - £7.00

Fuse Box: 4-Way Automotive Fuse Box - £6.00

Battery Lead: Ring Terminals, inline fuse and 'Anderson' connector - £5.00

Terminal Block: 4-Row Terminal Strip - £5.50

Panel Connectors: Generic MC4 Connectors - £5.50

Panel Mount: 4x Plastic Mounts - £13.99

Mounting: 10mm Plywood Sheet (400mm x 300mm) - £10.00

Backing Plate: 2mm Aluminium sheet (200mm x 130mm) - £3.50

Cable: 15A Red / Black - £3.00

Bolts: M8 Galvanised - £4.50

Misc: Fork Terminals & Spade Fuses - £2

Total Cost of build: £217.99

This cost can be reduced significantly if you chose a lower wattage panel & smaller battery capacity. I'm sure if you shop around some more on eBay most of the components could probably be found cheaper as well.

Step 2: The Build

For me, the fun part of this project was always going to be the build. I decided I wanted to mount most of the main components on a distribution board which could constructed and then be simply installed and connected in the shed. I chose to use a sheet of 10mm Plywood on which I laid out the controller, connection terminal blocks, fuse and fuse box. The controller itself came with a warning stating that the rear was actually a heat-sink and this should be considered when mounting. I first considered 'stepping' it away from the plywood therefore giving it an air-gap between the rear of the controller and the wood but finally decided to mount it onto a aluminium plate to help dissipate the heat. I cut the sheet about 15mm wider than the controller and rounded the corners (just for aesthetics), marked and drilled the four holes and then screwed it in behind the controller.

I drilled several holes in the board to allow me to run and feed the cable in from behind rather than cluttering up the front. Terminal blocks were placed in proximity to their controller terminals and the 'output' side of the distribution board situated to the right hand side. The output cable from the controller is passed through a hole to the rear of the board and then run out again above the fuse box.

From there I wired the switch (there was a reason for a 2-gang switch which I will go into later in the instructable) and ran the cable that would connect to the LED Strip and finally tacked it all in place. The shed is roughly 2.5m long so the 5m LED strip could be cut half way and mounted either side of the centre beam in the roof (and connected at the far end with a small piece of cable run between the two)

For the solar panel, luckily the shed faces north / south so one half of the roof was south-facing and therefore perfect for maximum exposure of sunlight. The panel was bolted to the panel mounts (using M8 bolts) and then bolted to the roof of the shed (again, using M8 bolts) with butterfly nuts to allow for easy removal. The mounts allow air to flow under the panel as well as channelling it over the top to reduce the risk of it being torn off in high winds. I constructed a cable with MC4 Connectors on one end to connect to the panel, and fed the other end back into the shed through a hole I had drilled. I then passed it from behind the panel through one of the holes and crimped on the fork terminals before attaching them to the terminal block. All other cables were prepared in a similar fashion.

The Anderson plug on the battery lead is quite an 'industrial' piece of kit! The pins can be crimped if you've got a tool that's up to the job however I used a small pencil blowtorch and soldered the cable into the pins instead.

Fuses are really important in a system like this. 12v systems aren't generally considered dangerous and are therefore perfect for this use; however there is a real possibility that a short circuit could cause a fire. As I've already said, the controller is able to deal with shorts in the output side but we should also make sure we protect the battery too. The lead I chose (see photo) to connect the battery to the charge controller has an inline spade fuse (which is currently a 10A). The output side also has a fuse to protect the lights from shorting damage too. Currently I am using a 5A fuse on that side.

Finally, using what was left of the sheet of plywood, I made a box to place the battery in as it was going to live on the floor, I wanted to protect it from wear, tear, knocks and bangs.

Step 3: Switching On

As soon as I plugged in the MC4 connectors to the panel, the charge controller came to life and started giving readings of charge rate, panel output etc.

It took a bit of fiddling around with the controller before I understood the settings.... unfortunately the manual that came with the eSky controller was lacking in its English translation!

I mentioned earlier that I'd chosen to use a 2-gang switch.... the reason for this is that I wanted to fit a second strip of LEDS that could be controlled independently..... a red set! I'm an amateur astronomer and it's a real challenge to set everything up in the dark.... however using a torch or turning on a normal light destroys the sensitivity of the eye... unless it's red light. Fitting this second strip means I can use the shed light to illuminate the area while I am setting up and even as a place to sit and remotely observe (using a laptop etc.) if it's really cold outside!

The one question I wanted answering when I was first researching this was 'How long will my battery last with the lights turned on'. This is actually far more difficult to answer than I first thought. Theoretically my 35Ah battery should be able to deliver 1A for 35 hours before its exhausted. The white LED strip draws 1.5A so this would mean about 23 hours of operation with a full battery. The problem is that these are just the theoretical values.... they don't take into account variables such as temperature & battery health which affect things massively. The other thing to consider is that lead-acid batteries don't operate anywhere near the theoretical maximum.... in fact at best you should expect about half of what is potentially possible. Saying that.... if it powered those strips for 10 hours, I'm happy with that!

Charging performance also relies heavily on external variables, not least the need for direct sunlight. With this in mind it follows that your battery will charge much better in the spring / summer months than during the rest of the year. Charge time is very difficult to calculate and until I have a monitor installed I can't say how this rig performs.

Step 4: Future Expansion

I am planning several more instructables covering a home automation and monitoring system I am currently implementing. One module of this will be a solar charge monitor which will feedback information about current battery charge, panel output etc. from this system. Once I've finished it, I will link it back to this instructable for continuity.

I am also looking into using the battery to power a mains invertor to allow 240v operation of some items of equipment for short periods of time.

Step 5: Any Questions?

That's about it for this first instructable from me. I hope that you've found it useful and would ask if you think I've missed anything, have something wrong or have any general questions, please don't hesitate to ask in the comments section below.

<p>Nice and well put together. If you use those LEDs with built in constant current drivers, your load on the battery will be much less. Those LED strips with the tiny SMD resistors are huge power wasters. Great first instructable!</p>
<p>Thank you :-)</p>
<p>Nice project and equally nice layout and lead dressing. I have a workshop but since I use some serious power tools and even a large compressor, the option of solar wiring isn't a realistic idea for anything other then maybe lighting. But I do like your project.</p>
<p>Thank you very much :-)</p>
<p>Great information on solar panels! Thanks for sharing! </p>
<p>Thank you</p>
Thanks for the information, good instructable, how's it going now?
<p>Thank you. It's been working well through the summer and the battery has been treated to a good steady charge. Now we are heading into the winter, I will be interested to see how it does. </p><p>I am in the middle of building a solar charge monitor which broadcasts MQTT messages over Wifi to my openHAB server. This will allow me to monitor the state of the battery and also the charge from the panel.</p><p> I will be putting together an Instructable for this shortly.</p>
<p>Good clean work. Please if you have a picture of the back panel i will like to see it. Thank you</p>
<p>Thanks :-) There is nothing happening behind. I just routed the cables through to keep the front of the board tidy.</p>
<p>I like this a lot. Good work!</p><p>I want to make something similar for my chicken coop.</p>
<p>Thanks :-)</p>
<p>love the project!</p><p>please vote for my solar shed in the solar contest</p>
<p>Thanks Chris. Love your implementation. All voted :-)</p>
<p>I love this I'ble! Just what I needed to get power out to our gazebo/tiki bar. My only question is on the 1st pic with your controller mounted, how is the far right terminal block wired? Specifically, where do the wires go from the bottom of the block and the top of the fuse block.</p><p>For the other 2 terminal blocks it looks like the lower side is connecting to the solar panel and battery, but the far right terminal block and fuse block I cannot see a label and tell what they are connecting.</p>
<p>Thank you :-) Glad it's helped with your project.<br><br>OK, as you identified, the two terminal blocks under the controller are for the battery and solar panel. Ignore them. If you notice there is a red/black pair that come from the far right connector of the contoller and disappear through the board. They reappear above the fuse block and connect to a single fuse. From there into a terminal block where they are split into two outputs (which then go back behind the board and you'll notice exit right) and on to switches and the LED strips. The terminal block is used purely to split the single output and allow for future expansion if needed.</p><p>It is the same as the diagram below the main photo apart from it splits into two after the fuse block. There is nothing clever happening behind the board, I wanted to route the cables that way to keep the front side as tidy as possible.</p><p>If you need anymore info, just shout :-)</p>
<p>You didn't mention what kind of floor your shop has but you can ruin a battery by storing it on a bare concrete floor. Also, the latest information I've seen suggests there is little evidence supporting the red light preserving night vision theory. So much for generations of sailors stumbling around in darken cabins by a red glow. </p>
<p>No it's a wood floor and the battery is in a wooden box. I've never heard that keeping a battery on a concrete floor can ruin it?!?<br><br><br>I appreciate there is speculation about red light however I can assure you, as an astronomer, it is most definitely beneficial to preserving night vision when you compare it to any other light source colour. If I expose me eyes to any normal light, the sensitivity is completely destroyed for at least 30 mins. I don't think you'll find many astronomers who'd agree with your claims.</p>
I didn't say anything about exposing your eye to normal white light did I?
<p>You will find very sailors that will agree with your red light/night vision analysis. We could see just fine in the red light. And when going into a room rigged for black (control room of submarine at night) we could still see if we entered from a room rigged for red, if we had been in the room with red light long enough for our eyes to adjust.</p>
I was just going by a recent scientific study using the latest measurement tools. They were probably lying for whatever reason.
<p>low level white had taken the place of the &quot;Red Glow&quot; preserving night vision. Giving an improved ability to operate more productively in the dark.</p>
<p>This is a bunch of hoo haw...</p><p>&quot;you can ruin a battery by storing it on a bare concrete floor.&quot; </p><p><a href="http://www.cartalk.com/content/business-batteries-and-concrete-floors-needs-be" rel="nofollow">http://www.cartalk.com/content/business-batteries-...</a></p><br>
<p>Congratulations on your Second Prize finish!</p>
<p>Thank you :-)</p>
<p>Great fit and finish for a nice project. I voted for it in Renewable Energy</p>
Thank you so much :-)
<p>Good job and well thought out but stainless steel is one of the worst conductors of heat. also hard to cut and drill. A sheet of alluminium would work better, 1mm thick would work fine and much easier to cut and drill.I fold some &quot; wings &quot; on the sides to get more metal exposed to the airflow. It gets hot in my shed in the summer and I haven't had a problem with it , yet.</p>
<p>My fault, that was a mistake. It was indeed aluminium and not stainless as I originally put! Thanks :-)</p>
<p> .did you make in england .</p><p>where did you buy the PV pannel</p>
<p>Hi dilligaf, yes I'm in the UK. I bought it from Amazon.</p><p><a href="https://www.amazon.co.uk/gp/product/B00HTSVDAM">https://www.amazon.co.uk/gp/product/B00HTSVDAM</a></p>
<p>You wrote. Theoretically my 35Ah battery should be able to deliver 1A for 35 hours before its exhausted.</p><p>A 12V battery is full at 12.7 Volt and empty at 11.8 Volt. Consider a cut out switch to prevent damage to your battery. In a camper we use 250 mAH Batteries.</p><p><a href="https://www.instructables.com/id/Battery-protector-cut-out-switch-with-ATtiny85-for/">https://www.instructables.com/id/Battery-protector-...</a></p>
<p>&quot;In a camper we use 250 mAH Batteries.&quot;</p><p>Really, do you mean 250 AH instead?</p>
<p>No.... definitely AH. mAH is more commonly associated with small batteries such as AA, AAA etc</p>
<p>Indeed..... however the Charge Controller I've used actually takes care of that and prevents the load from draining the battery to a detrimental level. I'll update the article to reflect this :-)</p>
<p>It is possible to use Solar panels to supply power for Power tools and industrial Air compressor and for a whole shop! However you have to Properly SIZE the &quot;System&quot; to be able to meet those power needs! Depending on the number and type of tools and the power needs of the tools you could be looking at between $35,000 to well over $100,000 USD for the whole system! The would be the Solar Panels, mounting (roof or ground)*, inverter, Batteries, and other items. <br> * = if you decide to go with a &quot;tracking&quot; system that can greatly increase the cost but will also increase the efficiency of the solar system. <br><br>But you can start small and add little by little until you have your whole shop or your whole house powered by solar! How? Buy a 2 panel kit or 2 panels and everything else to install them plus a few &quot;Deep Cycle batteries&quot; and use them as a &quot;back up system. Then later buy 2 more panels or as many as you can afford and also add more batteries, keep doing that until you have a large enough system to go &quot;off grid&quot;/power your whole whose, power your whole shop or meet all of your needs! </p>
<p>i made some solar systems course, and you need to consider 2 more thinks</p><p><strong>Cable:</strong> the expert recommend use XLPE cable, they are UV resistents, no use regular AWG cable.</p><p>also the <strong>Bolts</strong>, the solar panel are bulid in aluminium frame, so you must have to use a stainless steels bolt to avoid the galvanic corrosion.</p><blockquote><strong>Galvanic corrosion</strong> is an <a href="https://en.wikipedia.org/wiki/Electrochemical" rel="nofollow">electrochemical</a> process in which one <a href="https://en.wikipedia.org/wiki/Metal" rel="nofollow">metal</a> <a href="https://en.wikipedia.org/wiki/Corrosion" rel="nofollow">corrodes</a> preferentially to another when both metals are in electrical contact, in the presence of an <a href="https://en.wikipedia.org/wiki/Electrolyte" rel="nofollow">electrolyte</a>. This same galvanic reaction is exploited in <a href="https://en.wikipedia.org/wiki/Primary_batteries" rel="nofollow">primary batteries</a> to generate an electrical voltage<br></blockquote>
<p>Very nice instructable!</p><p>I made mine on my van here (<a>https://www.instructables.com/id/Mobile-Solar-Power...</a>, also to be used for camping/astronomy. </p><p>Lead acid batteries can out gas hydrogen when charging so be sure the vent them properly!</p><p>Is the battery a deep cycle? You might want a deep cycle battery or you'll want to discharge it only a little bit to give the battery a long life.</p><p>Back of the napkin calculations: If you want only 50% discharge on your battery then each night you will use at most 17 amp hours. Your 100 watt outputs say 7 amp hours in full sunlight and therefore should replenish the energy used in maybe 3 hours of sunlight. Looks like a good fit for low, winter sun. You'll produce more energy than you can store in the other seasons. You may want to consider adding another battery when your pocketbook can take it to be sure you can continue to have lights after three cloudy days.</p><p>Again, it was a very nice instructable!</p><p>Thanks!</p>
<p>I am going to check into this, I would like to install a shed at our camp and put this in? Would I have to disconnect in the winter so the battery doesn't get overcharged as we will not be using! </p>
<p>No you will not need to disconnect the batteries, the charge controller will maintain the charge to the batteries. That is the function of the charge controller.</p>
<p>I bought 4 used solar panels for $60US. A bargain. Unfortunately, they were 48V panels removed from service at a local warehouse. I did find a 48V MPPT and it works perfectly managing four 12V batteries in series. A bucking converter gives me some 12V DC for the LED string lights, Here is the SURPRISE! Standard 120V AC dimmable (they have to be dimmable) lamps work well without an inverter. My estimate is 70% of full output with 48V DC input. The 120V AC LED lights in the shop stay on all the time. I turn on other lights if I need more illumination. What started out as a big mistake ended up working well.</p>
<p>Hi</p><p>interesting, just started a similar setup.</p><p>charge controller mounted with 12v PC fans <br>2 x outdoor 12v 10w Spotlights<br>2 x 5m strip LEDs inside shed<br>12v lighting on/in decking<br>car stereo and waterproof speakers for outside entertaining :o)</p><p>controlled from a 4ch RF Remote</p><p>any chance of a picture of the back of the panel - just for curiosity</p><p>thanks again</p><p>mark</p>
<p>Well explained, you had a goal.. and used the knowledge you had to achieve that goal! As built, your system should serve admirably until you start messing with it, which is inevitable. Trust me, my new solar-experimenting Brudda! LOL</p>
great project, i am going todo this :)
<p>I've read the gains for MPPT are only realized when your PV system is much higher voltage than your load (&gt;100V). if your PV matched in voltage to your battery/load then you're just as well off with a cheaper PWM controller.</p><p>The MPPT converts excess volts to more amps for charging where the PWM loadsheds the excess voltage as heat. </p>
<p>Thanks for clarifying those points Malkaris :-)</p>
<p>actually it appears you are using a PWM (not MPPT) controller.</p><p><a href="http://solarcraft.net/articles/comparing-pwm-and-mppt-charge-controllers/" rel="nofollow">http://solarcraft.net/articles/comparing-pwm-and-m...</a></p>

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