This instructable outlines a portable solar charging station, stereo, and LED light that is built into a playmate cooler. It is an all-in-one portable unit, as you can charge your phone or tablet with solar power, fill a room/beach/field with music, and also have an area light.

You can set this up at your home for everyday charging of your devices, and easily bring it with you for a day on the beach, on a camping trip, or anywhere else. It can be very useful during power outages, or even be a prime source of power in an off-grid cabin or home.

The design of this unit is very flexible, and you can choose features or expand on this to meet your specific needs. You can also take advantage of using scrap parts for its construction, with old car audio components, scrap wood, and spare wire that you might have lying around. I've found that you can borrow from a lot of "car accessories" that are 12V DC powered, or even use a small inverter for AC loads, to use this solar power for a wide range of devices.

Step 1: Parts


I chose the 16 Quart Igloo Playmate cooler for this build, since it's big enough to hold everything, but still small enough to carry with one hand. The roll top is also quite useful, and makes access to everything very easy. (~$20, Target/elsewhere)


I used an scrap laminated bookshelf to mount everything on. I've used thin plywood for this before, but a thicker piece of wood makes the acoustics much better. (free/scrap)


Any standard 12V auto/marine stereo deck will work. I used a basic marine unit, since it somewhat more water resistant than a standard car deck. The cheaper units are "Mech-less" and have no cd-player. You could reuse an old unit, and go pick up a used deck from a junk yard / scrap exchange. ($30+ depending on features, Amazon/elsewhere)


I used a pair of 5.25", 150 Watt, 2-way marine speakers, which fit quite nicely given the playmate dimensions. While you could use regular car speakers, marine speakers are waterproof (in theory) and are usually built to take more impact and abuse. Again, this is a spot where you could pick these up on the cheap as used car parts. (~$20, Amazon/elsewhere)


Small 12V AGM lead-acid batteries are very easy to find, as they are used in computer UPS units and fire-alarm systems. Like all batteries, their capacity is rated in Amp-Hours (Ah). Choosing the battery size is a trade-off between Ah capacity and weight, as this is by far the heaviest part. I chose to use two 12V, 8Ah batteries (wired in parallel for a total of 16Ah). At moderate volume, my stereo draws approximately 1 Amp, so in theory I could play music for 16 hours if I drained the battery from 100% to empty. Admittedly, this is overkill, you could get by with 5 - 10 Ah. (~$20 for a 8 Ah battery)

Solar Panel:

Solar panels are getting cheaper by the day, and you can find a small one on eBay or elsewhere fairly easily. Since the battery is 12V, you want a solar panel that is rated for 12V. The "open-circuit voltage" of a 12V solar panel will be around 18V, but the charge controller will prevent overcharging. The size of the panel should depend on the battery size. As a starting point, I would suggest matching the wattage of the panel to the amp hour rating of the battery (10 Ah battery, 10 W panel), but also considering what loads you will have (a stereo will draw 5 - 20+ W). A 10 W panel will have an effective charging current of approximately 0.6 amps (10W / 18V), which will charge your battery from half to full in about 8 hours of full sun light. I used a 10W solar panel, but this will depend on your needs. (~$35 for 10W panel, ebay)

Charge Controller:

If you want to charge the system with a solar panel, you will have to use a charge controller to connect it to the battery. These devices regulate the battery voltage and disconnect the solar panel when fully charged, preventing overcharging and damage to the battery. Find one that has a current rating greater than the "short circuit" current rating of the solar panel (the smallest you will see are typically rated for 5 - 10A). A basic unit will do, but I chose a nicer one that has the PCB sealed in epoxy, making it moisture tolerant.

Some units will have a low-voltage disconnect (LVD) function, which will shut off the loads if the battery voltage gets too low, preventing damage to your battery. ($20-$60, Amazon/elsewhere)


- Multiple DC toggle power switches ($5)

- Fuses and fuse holder for different DC loads ($10)

- 12V cigarette ligher socket for accessories ($5)

- Short lengths of wire (scrap/free)

- Drawer handle, to pull the faceplate out ($2)

- LED lights ($10)

Total project costs:

- As built: $250

- Basic components, with same features: $150, (less with used audio parts)

I have a question so if the main power is hooked to the toggle switch will the solar panel only charge the batterys when it is on??
thanks for the project it works great now I got ideas for a bigger one
<p>Awesome build - nice work!</p>
I have a question, how do I know what kind of controller to get? As far as wattage... and what kind did you use <br>
<p>Good question, it important to size this appropriately. Basically, you take the solar panel power rating (Watts), and divide it by 12 V (the typical nominal voltage). This will give you the rough maximum current you'll get out of the panel. Alternatively, some panels will list their &quot;Short Circuit Current (Isc)&quot;, which is the physical maximum current.</p><p>You want to choose a charge controller with a current rating that is greater than the short circuit/maximum current from the panel, plus about 25% in margin.</p><p>For my system, I have a 10 Watt panel. The power divided by the voltage is 10W / 12V = 0.83 Amps, while the stated short circuit current is 0.61 Amps. At this level, I would recommend a charge controller of 0.61 A + 25%, or about 0.76 Amps. This is a relatively small current, and most charge controllers will be at least 5 Amps. It's not a bad idea to build in a little extra capacity if you want to use a larger panel someday.</p><p>If you are using a Charge controller with a &quot;Low voltage disconnect&quot; feature, where you wire all of the loads THROUGH the charge controller, the other, likely more significant factor, is the amount of load current you want to pull. In my system, I sized the system to allow up to 10A of load current, so I have used a 10A charge controller.</p>
<p>I'm having trouble finding or figuring out what the DC bus and the DC distribution of the 6 circuits. Where would I find that to buy? A link would be nice for some help</p>
<p>If you search for &quot;fuse block&quot;, you should get a few different options come up. (You'll note that some also have a distribution block for the negative (-) rail of the DC bus, in addition to the fused positive (+)).</p><p>Here's a few links:</p><p><a href="http://www.amazon.com/ATO-ATC-FUSE-BLOCK-GANG/dp/B000N9PJ7W/ref=sr_1_7?ie=UTF8&qid=1435235360&sr=8-7&keywords=fuse+block" rel="nofollow">http://www.amazon.com/ATO-ATC-FUSE-BLOCK-GANG/dp/B...</a></p><p><a href="http://www.ebay.com/itm/ATO-ATC-Marine-Boat-RV-Fuse-Terminal-Block-6-Gang-Ground-Buss-Seachoice-13301-/291399832070?hash=item43d8c89206&vxp=mtr" rel="nofollow">http://www.ebay.com/itm/ATO-ATC-Marine-Boat-RV-Fus...</a></p><p>There are lots of ways you can wire up the DC bus, this is just a way that I found to be easy to break off the various circuits while also individually fusing them.</p>
<p>I love the cooler + light + charger + tunes idea, and the fit and finish of the project is great. BUT, you could make something half the weight, which sounds better, for substantially less money, by swapping only two components: The car stereo and the sealed lead acid batteries. </p><p>Even the lowliest cell phone, or a $25 clip-on mp3 player sounds worlds better than the tuner, CD player or USB media player in a $60 car stereo, and to boot, doesn't weigh anywhere near a few pounds. Likewise, a $30 class-D chip amp using the TPA3116 chip will produce the same power, at about 90% efficiency vs 50% for a typical class AB car stereo, at 12V, from a package the size of a pack of cigarettes. No bluetooth receiver sounds as good as using a simple input cable, but even $30 buys a packaged amp with an integral bluetooth receiver. Similarly, $25 buys a 6.8Ah lipo pack with a built in charging circuit that's half the size and &lt; 1/3 the weight of an 8Ah SLA pack. One of these packs will power the amp for as long as two of the SLA's will power a car stereo, or, if you use a second pack in series to feed the amp with 24V, you can get &gt; 30W RMS of clean power from a TPA3116 amp. Here's an example of the pack: </p><p><a href="http://www.ebay.com/itm/like/361097965880?lpid=82&chn=ps" rel="nofollow">http://www.ebay.com/itm/like/361097965880?lpid=82&amp;...</a></p><p>Here's a cute example of the general breed of amp I'm referring to: </p><p><a href="http://www.ebay.com/itm/271840326670" rel="nofollow">http://www.ebay.com/itm/271840326670</a></p><p>If you're chasing after similar fun in a cooler, why not take advantage of the source you already carry in your pocket, and modern advances in battery and amplifier tech?</p>
<p>Thanks for these ideas - this is something I'm going to check out and give a try! Part of the motivation behind using a 12V lead acid and standard car parts is that there is a huge amount of parts available and they are relatively easy to find and wire up. Additionally, almost all solar charge controllers that I've found have charging logic designed for lead-acid batteries. <br><br>But you have some really good examples of (newer-age) components, and you're absolutely right, these would go a long way in terms of weight &amp; efficiency. I'm going to give the li-ion pack a try, and see how interfacing a PV panel to it would work with the integrated charging circuit.</p>
I actually stumbled across your build after deciding to build something similar (tunes only, or I suppose a cold lunch as well) inside the next smaller size of Playmate cooler, the 9qt one. To keep it simple, the particular battery pack I'm talking about needs no special charging circuitry... It's built-in. You can charge it with anything in the neighborhood of 12V, which I'm sure your solar charge controller will happily supply. Yes, LiPO batteries need special charging circuitry, but if it's taken care of with these packs. (Sellers come and go, but I've see this same design since last fall all over the place, hence the photo in addition to the soon-to-be-over ebay link.) Same goes for the amp... just a photo of an especially value-packed example. First the TA2020, TA2024 amps, now these TPA3116 amps... I've never heard such bang for the buck. They really sound as good as vintage/tube iron when pushed gently. If you've got room for a 3rd driver in your cooler, (rare 6x9, rarer 8x10 or 8in?) or a pair of drivers on the other side (Tang Band W5-1138SM/SMF or W6-1139SL/SLF) there's an amp available as either a bare board, or nice finished piece w/ bluetooth, for $20-$60, that has a subwoofer output with a decent 2nd order crossover and twice the power of the main channels that can handle a 2ohm load. 24V may be overkill for this purpose, (and the TPA3116 amps are known to go into thermal shutdown when driven with 24V... I'm adding diodes to drop the voltage a bit,) ... I'd rather save $25 and a couple pounds. I'm also a fan of using potted electronics (or a water-tight inner enclosure) and marine / poly speakers and being able to use the cooler for it's intended purpose in addition to a boombox. Thanks again for posting this. Eric.
<p>Really well done. I notice that your wiring diagram and the pictures show fusing but it is not on your parts list nor is it emphsized how important it is. Fuses are cheap and much cheaper to replace than any of the other parts. </p>
<p>You're right, fuses are a very important part of any design using a 12V lead acid battery!</p>
hi, how many amps can the load side of the charge controller handle. can a 200 watt inverter be plugged/used at same time as music is playing, or would it be best to connect the inverter to battery?<br> thanks . nice instructable
If your charge controller doesn't specifically state the current rating for the &quot;load&quot; connection, I would assume it's the same as the current rating for the &quot;solar&quot; connection (in my case 10 A). For a 200 W inverter, the peak current draw would be approximately (200W / 12V) = 16.7A, which you should probably connect directly to the batter if this is over your charge controller current rating. The only downside of this is that you no longer have the Low Voltage Disconnect function, and have to remember to switch off the inverter to prevent deep-discharging your battery (however, most inverters will cut out at some low voltage, say 10V).
<p>Daft Punk is playing at my house.</p>
<p>Awsome project, I am definitely voting for you!</p>
<p>Thank you!</p>
<p>Fantastic! Very easily read, well explained, well thought out, and very well organized! I have been planning to make one of these myself for sometime, but unfortunately I have not acquired the power supply parts (and keep re-working the plans) so it never gets started. You got my votes, favorites, and hope that you inspired me to put all my parts together! Congrats and best wishes! </p>
<p>Thanks! And good luck with you own build!</p>
<p>Nice!!! I have to make one with bluetooth</p>
<p>I've used one of those aftermarket bluetooth adapters that plug into the 3.5mm aux jack on this system, but it has always been a little finicky with pairing to my devices. If you have the cash to spare, you can get a nicer stereo deck that has bluetooth built in.</p>
<p>can you list source for charge controller,strip LEDs and outlets/switches? What do you think you spent total? thanks, great build. I'm thinking of just doing the basic panel/contoller/output </p>
<p>I've updated the parts step with approximate costs, as built the total was about $250. I tried to build mine to the full monty, so it could certainly be done for half the cost or less, or even cheaper if you can get your hands on a used stereo deck (or don't use one at all).</p><p>I sourced most of the parts from ebay/Amazon (including the LEDs, charge controller, and switches), but shop around if you have any specialty scrap shops or junk yards in your area.</p>
<p>Great Idea. I've been looking to do something similar for a while. I have an old CD DJ case and loads of SLA's from an old UPS.</p><p>Was looking to add USB and cigarette lighter sockets, maybe have a cigarette lighter socket torch stored in there.</p><p>Have the option of mains or car charging.</p><p>Also might add some lugs to attach jump leads to get the car going.</p>
<p>Lovely build. I noticed you may have used some Sugru on the corners of the panel. Does the panel fit inside of the cooler for transportation?</p>
<p>Good eye, yes, it is Sugru on the panel. The panel that I bought had the standard aluminum frame, and the corners are rather sharp for the the purpose.</p><p>Yes, the 10W panel can just barely fit inside the top of the cooler. The sugru addition makes it a little too big, so I'll have to shave it down a tad.</p>
<p>Awesome build! Excellent and detailed write up as well! Great job :)</p>
nice &amp; easy ..
<p>This is amazing! It looks fantastic and you did a great job writing it up!</p>
This is awesome! The light is a nice touch.

About This Instructable


868 favorites


Bio: Electrical engineer by trade with a passion for tinkering at home
More by jtjaeger: Solar Charged Stereo Cooler
Add instructable to: