Introduction: The $120 DIY 12v Solar Power System
Here's my guide for a simple off-the-shelf and off-grid solar power system you can build yourself. I use this to power a Raspberry Pi that monitors my chicken coop, but you can use this in your RV, shed, garage, pool house, you name it.
What do you want to power? How many devices, how much current do they draw? The size of your solar panel and battery will determine that and can be upsized if needed. This guide will only cover what I need for my system.
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Step 1: Parts
Here's my build list, straight from Amazon. Search for the names and you should come up the exact same items. I've seen lots of similar things from Harbor Freight and other places too.
- instapark 30w solar panel with charge controller
- DROK Parallel To Dual USB Adapter 12V to 5V/1A
- 12v wire
- 12v battery
- (optional) 8 way terminal block
- (optional) Insulated Car Battery Clips Alligator Clamps
There are many varieties of solar panels, make sure the model you purchase comes with the charge controller. The variety I selected comes with small alligator clips to connect to the battery. If your battery has flat terminals it'll work great, otherwise you may need to buy additional clips.
My goal was to run a computer off 5v USB power, so I chose a 12v->5v/1A transformer. If you need more or less power, select a different transformer. If you want to power 12v stuff YOU DON"T NEED THE TRANSFORMER.
Buy new wire if you don't have any, otherwise feel free to recycle what you have as long as it's rated for 12v. Color matters, it will help down the road if you use RED for + and BLACK for -. Think about what you want to power, where it will be installed, and choose length accordingly.
Any 12v battery will do, old, new, however IT MUST WORK and be able to HOLD A CHARGE. Get a new one for your car, and use the old one. I bought a new tractor battery because it had a smaller footprint and smaller terminals.
How many things do you want to power? If you have a bunch of stuff you want to power up you will need to use a terminal block to safely distribute power. I wanted 12v AND 5v power, so I used a terminal block to wire it up. I The model of transformer I chose specifically because comes with 2 USB connections for easy 5v computer connections.
Step 2: Wiring
The solar panel you bought came with something called Solar Charge Controller. It does all the heavy lifting and provides the hookups you need. Connect the battery to the controller, connect the positive and negative leads from the solar panel to the controller, then connect your transformer to the load terminals.
The solar panel charge controller will come with a build sheet that has a wiring diagram and installation details. Read and use them, my instructions are very generic and are good enough to get you started.
*Extra bonus* - if you plan on hooking up more than one or two items to the load terminals on the solar charge controller, use a terminal block to safely provide power. If you choose to go this route, you can connect multiple transformers to give 5v, 9v, or whatever voltage you need. Keep in mind that the more devices connected, the more power will be used. You may need to upsize the battery and solar panel if you go wild.
Step 3: Installation
Plan out your wiring diagram and decide where the components will be installed. Use additional wire to separate the components and put them where you want them to be.
Most electrical devices like to be dry, so make sure the solar charger and battery go in a dry place. An alternative would be to place them in a waterproof (but not airtight) container.
Naturally the solar panel needs to be installed on the roof in a sunny location.
Plug in your stuff and enjoy being off the grid. I built a Raspberry Pi with camera to tweet photos of my chickens, but that is another instructable.
Thanks and enjoy, follow me on Twitter @peterhagemeyer or my chickens @NJchickens