My mobile solar photovoltaics system, plus added charging system for battery packs
I like to camp, and I like to have all the comforts of home when camping, including lights and other electrical devices. I built this system to go in a 1964 Dodge van I am currently restoring, but use it when camping out more than 3 days already.
Here is the van, with the 3 55 watt Arco Solar panels on top, for a total possible output of 165 watts, or +/- 10 amps. I need to clean them...
Next up is a milk crate with six 17 amp hour Gell Cell batteries, for a total amp-hour rating of 102 AH capacity. I have two more that are not in there at the moment, bringing me up to 136AH, but I can't lift the box with all in there...
Next, I have a wooden panel that sits on top of the batteries, and has distribution bars for the battery hookups, a charge controller, and a fuse panel with 10 circuits. I use Circuit breakers, instead of fuses though. 1 is installed. The mess is just the extra slack in the power feed wire from the panels, plus the power out to the boost converter.
So that's all been settled and running for a while. The new addition is a new Boost Converter. This boost converter lets me convert my nominal 12volt DC power into a higher voltage, up to 120 volts DC with about a 5% current loss. I purchased it so I can charge my 54 volt LiFePO battery pack for my E-bike, when off grid. Currently I am charging my car's battery with it, so I bumped the voltage from 12.5 to 13.8 as a test. I also adjusted it to run at a max of 6 amps.
And last piece, this is Watt/amp meter, installed inline. this is from the E-bike world. I really like it! It gives you volts, amps, watts, and AH readings.
Coming out of the watt meter is 20 feet of 12 gauge wire, going to my Toyota Camry, which has a dead battery. it was at 10.36 volts, and in 2 hours I brought it up to 12.4 volts. Going to let it run a bit longer.
I need to make a project box for the boost converter, and mount it with the rest of the panel. I also feed 2 DC-AC inverters with this system. A 1200 watt unit for power tools, and a 200 watt unit for little things. What I built here is modularity and mobility. It isn't pretty, but it is very solid.
As always, if you like my original content, please upvote/resteem/follow me @dawg-boy
seeing how you are using 3 12v panels; have you thought about getting a MPPT charge controller and running them in series (36V) so that you can get charge out them even under partial shade/ earlier in the day? I have been looking into MPPT controllers as a way to get maximum efficiency out of a small (mobile) solar setup like yours.
I could, but I will have to run a converter back to 12volts for most of what gets run from it.I could easily reconfigure the battery bank though. so that's a plus.
the MPPT can be set to charge 12V. That's one of the ways it is able to gain efficiency. When the panels are at 1/2 voltage (shade, or when the sun is oblique), they will still be at 18V, so the charger is able to charge your batteries... At full power, the MPPT charger determines the maximum power it can extract from the panels and charges the batteries at that rate (for bulk charging).
running the panels in series, and higher voltage, also allows for smaller wire to be run from the panels to the charger...
The chargers are expensive, and on small setups its usually cheaper to add another panel to gain WH, but with our systems being constrained on size (they need to fit on a vehicle) adding panels is not always an option...