This Instructable is on how to build a battery power pack that charges from the sun. I built it this past summer to have a portable device that I could run and charge my  gadgets on.

Step 1: Wiring Diagram

The first thing I did was draw a wiring diagram.

Step 2: The Parts

Next I shopped around and purchased my parts.
Below is a list of the parts I used.

Solar Panel - - - - - - - - - - - - $68.95
12 volt battery - - - - - - - - - - $58.00
400 watt inverter - - - - - - - - $21.99
rolling toolbox - - - - - - - - - - $22.88
auxiliary 12 volt plug - - - - - $4.87
auxiliary 12 volt plug - - - - - $4.87
14 gauge wire (red) - - - - - $2.48
14 gauge wire (black) - - - $2.48
heat shrink ring conectors- $2.45
3/16'' heat shrink tube - - - $1.99
bridge rectifier - - - - - - - - $1.99
SPST switch - - - - - - - - - - $2.99
utility - - - - - - - - - - - - - - - - $.54
solder - - - - - - - - - - - - - - - $1.49

total - - - - - - - - - - - - - - - - - $197.97

My battery is a 12 volt deep cycle battery. Deep cycle batteries are
made to be fully charged and discharged; unlike car batteries which
are not supposed to be fully discharged. The battery is rated 75 amp hours.

The inverter converts the battery power (DC) into regular AC power.
The inverter is rated 400 watts.

I bought the solar panel at a farm supply store.
The Solar Panel is rated 5 Watts.

I bought this toolbox because I thought everything would fit in it well,
and it had wheels which would make it easier to transport.


Step 3: Battery Mount

I built a battery mount out of 2X4's to hold the battery in place in the toolbox.


Step 4: Pre-Wiring

Before I started wiring I had to put in a utility box for all the
connections. I removed three of the punch outs on the utility box;
the middle bottom one, the middle side one, and the one end one.

I screwed on and tightened a compression fitting on one end.
That is where the wires going to the 12 volt plug will go through.

Step 5: Installing Power Input Plug

Next I cut a hole for the input power plug. I mounted it so that
the connection end of the input plug would go directly into the
utility box.

Step 6: Hole for Battery Wires

Then I cut a hole under the utility box for the wires going to the battery.

Step 7: Preparing the Wires

In preparation for soldering, I crimped ring conectors on one end of both the positive and negative battery wires. Once they were on, I used a lighter to shrink the heat shrink tube on the ring conector.

The 12 volt plug I bought came with the 2 wires I needed, but because the power input plug went right into the utility box I didn’t need the wires to be so long, so I cut them really short and stripped them off.


Step 8: Soldering

I ran the battery wires up though the hole in the bottom of the utility box and soldered everything together. To keep them from shorting out I put heat shrink tube on all the connections. Next I tightened the compression fittings to prevent the wires from being pulled out. Since all the connections in the utility box had been made, I screwed the lid on.

Step 9: Installing the Power Output Jack

I found where I wanted to mount the 12 volt power plug, drilled holes and bolted it on.

Step 10: Wiring for the Inverter

First I drilled holes and ran the two wires through. Then I cut and stripped the wires just long enough to reach to the battery from the inverter. After that I crimped small ring connectors on the inverter ends of the wires and large ones on the battery ends. Once both ends of both wires had ring connectors, I shrunk the heat shrink with a lighter.

Step 11: Finishing Up

When you are finished, plug it into the solar panel and charge it. Once it's charged you'll be able to use free power from the sun.

If you have any questions I would be glad to answer them. Also feel free to post pictures of your own creations.

Where did you buy your inverter?
I bought it at meijer for $21.99.There are also many other places you can get them from. If you don't have a meijer near your house, you could get one from a hardware store or from Northerntools.com<br />
ok, thank you. I am planing on building 1 for myself<br />
Cool; post pictures when you are done.<br />
ok<br />
Yeah, good work!&nbsp;<br /> I&nbsp;plan to make my own - but with&nbsp;a bit modification:<br /> I&nbsp;won't have your bridge rectifier - just a diode (still don't know how I choose which type)<br /> Is your SPST&nbsp;switch for the solar panel charging the battery?&nbsp;Why?<br /> I was going to have the solar panel always connected to the battery - with a trickle charge indicator that will shut off current into the battery.<br /> Then, for outputs I'm going to also add a USB&nbsp;port along with standard wall plug.<br /> <br /> Have fun with your project, it's the best damn idea people don't have yet!
<p>Yes, the SPST is for the solar panel charging the battery. The reason why is because I didn't install a charge controller that prevents overcharging and so I put a switch to control charging manually. Also mine does have a 2 standard wall plugs and a USB port; that is what the inverter is for.</p>
I'm just learning electrical systems and engineering - If I&nbsp;wanted to bypass the rectifier (I don't have any plans with wind turbines!) what type of diode would I use &amp; rating, and how would that change this layout?<br /> <br /> I've been planning on making this for a long time and I&nbsp;thank you for your effort on this DIY!
If you use the solar panel I use, you won't actually need to&nbsp;install&nbsp;a diode because the solar panel has one built in.
Can you send me a proper diagram or advise to build a system for my power chair. Im a vet and like to spend time outdoors but cant in most cases because of rechargeable sources. My chair has 2 gell cell batteries with a regular charger. Wonder if I could go direct panel to my batteries. <br><br>Please, please advise. Thanks
<p>You have several good options to charge your scooter. You can charge your scooter from your car using an inverter you plug into your car's lighter outlet. You can charge your scooter from an extra car battery you take with you (you'll still need an inverter for that). You can use a solar panel and run that into a Duracell power pack, thereby removing the need for any wiring. Duracell, for example makes a backup power pack that will charge with a (external) solar panel. Cheapest option is to use an inverter from your car lighter, because your car is already a generator. For a hundred bucks you can get an inverter that will not only charge your scooter, but run your fridge in the event of a power outage, turning your car into a backup generator on wheels. </p><p>Now if you want solar power for camping, I would go with the largest solar panel you can carry safely, and a Wagan or Duracell power pack (or two as you can link them). a 100 watt panel can be had for about a hundred dollars, and a Duracell power pack can be had for about 120. but with those two, These powerpacks come with built in USB and built in 110V output. Make sure the scooter AC power draw in wattage is less than the max wattage of the power pack. Small solar panels (&lt;15 w) would take days to fully charge a depleted scooter. The bigger the wattage of the solar panel the faster it will charge your backup battery. I would not recommend hooking up your scooter to a solar panel, unless you have a voltage regulator made for the exact volts of your scooter system. </p><p>Hope that helps. Thanks for your military service!</p><p>(also a veteran)</p><p>v</p>
<p>Do you plan to plug into AC power to charge before heading out? Any plans to retrofit?</p>
Yes I do often charge it before taking it out. You can use a standard battery charger or maintainer
<p>Why is the bridge rectifier needed, as I thought the solar panel's output is DC?</p>
It's not actually needed. I was confused on the purpose of a bridge rectifier vs a diode which should have been used. In fact, the panel I used has a built in diode so wouldn't have needed to install one at all
<p>How many AmpHours is the battery? I have a 17Ah, what output could i get from this?<br>Great instructo!</p>
Mine is rated 75 amp/hr (I tell about it in detail in step 2)<br><br>A 12 volt 17Ah battery would equal out to about 200 watt hours. That means, for example, you could run something with a 50 watt draw for 4 hours
<p>I would really like to build one of these for myself. Could you use a automotive style voltage regulator to keep from over charging your battery? Or is that completely different from something you would use with a solar panel? Any info is appreciated Thanks</p>
<p>I'm not sure what type of regulator you are referring to. With a panel as small as I used, you wouldn't have to worry about over charging the battery. Many larger solar panel set ups come with a charge controller, or you can buy one for a reasonable price online; just search &quot;solar charge controller&quot;</p>
have you thought about using two batteries and a charger controller with a 15 watt solar cell then yo could in stall a larger inverter and use it as a full generator for work applications and possibly even build them to sell and make a business I use similar setups for long camping trips wish I would have thought about a rolling tool box though
Thanks for the suggestion. Since I made this instructable I have made a couple more and sold. The one had a larger 101 Amp/hr battery with a 15 Watt panel. The last one I built had a 101 amp/hr battery, three 15 watt solar panels, and a 900 Watt inverter
I'm curious about whether this will function as both powering something (like the stereo in the picture) while still charging from the solar panel, all at the same time. Or is it a choice of one or the other?
You can plug into the panels to charge and power a stereo or whatever else you want at the same time
That's awesome, thanks for everything!
Dave, great project. Can you provide more information on the bridge rectifier? Brand / Nomenclature? Where did you install it in your toolbox? Thanks.
I think it would be a good idea to also add some ventilation to this just to help with efficiency in a situation where you would want the lid down. it looks like you have the lid closed with the Solar panel on top for support. If there are no vent ports, the inverter will heat up. Without a charge controller this could be even more important for your battery. Your solar array probably isn't large enough to cause a major problem, but on a small scale, heat reduces your efficiency.
If I have 2 40watt 20volt solar panels that is connected to two CSB gp12650 12V 65Ah batteries, how much watt of inverter do I need? If I fully charged the batteries (includes the solar is still running) and connect to a window unit air condition that sucks up 900 watt, how long will the A/C last?
2 X 40 Watts = 80 Watts<br> 12 hrs. of sunlight everyday X 80 Watts = 960 Watts<br> <br> Every day you could use the air conditioning for only 1 hour. If you are running the air conditioner on the inverter you would need an inverter that was at least 900 Watts. In my opinion if you want some kind of air conditioning I would suggest making one of these-<a href="https://www.instructables.com/id/Portable-12V-Air-Conditioner---Cheap-and-easy!/">https://www.instructables.com/id/Portable-12V-Air-Conditioner---Cheap-and-easy!/</a>&nbsp;-This one even runs on 12 volt so you wouldn't even need an inverter.
What is the Wattage on your solar panel?
The one shown is a 5 Watt panel, but since then I have bought a 15 Watt panel which is what I now use.
Instead of using a big inventer! can you use a small in-car inventer.<br>
Yes, actually that is what I originally planned to use but I found the 400 Watt inverter on sale so I decided to use it instead.
can i use a 1000 watt inventer instead of 400 watt one?<br>
where did you get the solar panel and what voltage and amperage is it?
I bought mine at Tractor Supply Co.( <a href="http://www.tractorsupply.com">http://www.tractorsupply.com</a>) But since then I have found them for cheaper at menards and Northern Tools (<a href="http://www.northerntool.com">http://www.northerntool.com</a>) The one shown is&nbsp;~15 Volt&nbsp;and only 1/3 Amp,&nbsp;but I now usually use a 15volt 1 Amp panel.
This generator is a big help to some home owners. This is a plus factor that can<br>save energy as well as money. Solar energy is an advantage to those who wants<br>to save energy and won't spend much money.<br><br>Great post. Keep sharing.
were did u buy the tool box for 22.50 at. what store
I bought it at walmart
thanks alot for info
&nbsp;So this 12v plug is just running straight of the solar panel and not the battery correct?
This is the power output&nbsp;plug to plug in things such as a cell phone car charger. The plug in step 5 is the input plug for the solar panel. Both the output and input&nbsp;plugs&nbsp;are connected&nbsp;to the battery.
&nbsp;oo ok, doesn't your diagram show an output car 12v plug? &nbsp;I thought that was what this was
Yes, this one is the output plug.
&nbsp;What size of a panel and an inverter would you need to run a hot plate and an small electric room size heater? Does anyone know and would be able to help me? Can I do that? Thanks, Patricia
<p>Patricia,</p> <p>As Spanbox and isacco have said this setup is too small for running heaters and hotplates.</p> <p>What I would suggest for a heater (if you're wanting something portable) is that you should get a small propane heater such as this one. <br /> <a href="http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200362083_200362083" rel="nofollow">http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200362083_200362083</a></p>
A solar system would be very expensive to do what you want. Generating heat from electricity requires <strong>a lot</strong> of electricity. Solar systems, batteries and inverters are never 100% efficient either, so, to use a 1000W heater or hotplate for 1 hour you would&nbsp; need about 1200W/h of stored energy.<br /> At 12V, 1200W will draw 100amps. So, if you have a fully charged 100A/h battery it would be dead after 1 hour, but draining any battery is bad for the battery.<br /> Better would be to have 5 x 100A/h so that each one only uses 20% after 1 hour, and stays 80% charged. A 100A/h deep cyle leisure/solar battery does not come cheap, let alone 5 of them. Then you need an expensive inverter capable of the high load, and then enough solar panels to charge the batteries again.<br /> <br /> I would think about trying to use a different method for generating heat e.g. a gas fire or a gas hotplate. Wood is also carbon neutral and a good source of renewable energy.<br /> <br /> Hope this helps.<br />
Usually, a hot plate or an electric heater has between 500 and 1000 watts of power consumption. A Silicium mono-chrystal panel delivers a nominal (maximum) power of about 100W per square meter. The battery and inverter should be sized on this power. It would not be a portable system.<br /> <br /> Isacco<br />
&nbsp;I could purchase enough panels and an inverter I saw from Coleman was rated at 100o W. But, I don't know what I would need in batteries. Can you help? Thanks

About This Instructable




Bio: "CAN'T can't do anything until TRY comes along and does it" -Grandpa
More by DIY Dave:Photography Soft Box Backdrop DIY Wind Turbine How to remove 5 gallon bucket lids 
Add instructable to: