Question regarding Solar build

[Cussewago Rifleman]

Hi all,

I am currently building a 400 ish watt system using Will’s book and videos.

My current setup is a 2200 watt pure sine wave inverte, epever 40 amp mppt charge controller, LIFePo4 batteries.

I pick up 4 of these panels locally and was double checking to see if using one of these panels for my little system. Also note, I am mounting my components to plywood and mounting the plywood to a dolly to making it portable. I am intending to make a portable ground mount for the lone panel to use with this setup.

Thanks in advance for feedback.

Here is a pic of the specs on the back of the panel:

 

[Rednecktek]

Nominal system voltage? With 1 of those panels you'll max out that SCC you have. Fortunately that's a pretty good match if you're running a 12v system or you could run a pair of those if you go 24v.

 

[Cussewago Rifleman]

Nominal system voltage? With 1 of those panels you'll max out that SCC you have. Fortunately that's a pretty good match if you're running a 12v system or you could run a pair of those if you go 24v.

12 volt currently but could switch to 24volt if i bought a different inverter…

 

[MrM1]

I'd buy a 24v inverter if it's an easy option . Smaller wires

 

[Rednecktek]

Rule of thumb when sizing controllers is 10a of SCC per 100w of panel @ 12v, so that 40a SCC is maxed out on one panel.

 

[MichaelK]

Unless your application has wheels, I personally think you are better off at 24V. But, here's a strategy to utilize extra panels either at 12V or 24V.

Your controller has an Amp limit of 40A, and just one panel on paper would be 445W/12.5Vcharging = 35.6A. In the real-world though, I usually use a derating value of 85%, which means what you'll actually get from your panel around noon is really 30-31A. So, assuming you tried to wire up two panels in parallel, and they're feeding 750+watts into the controller, anything above 40A gets wasted.

An alternative is virtual tracking, that is having panels pointed in different directions. So, at 12V, you might have one panel pointed East, the second pointed South, and a third pointed West. This would mean you are making the same amounts of watts over a longer period of the day, without surpassing your amp limit.

If you switched to 24V instead, a somewhat better option would be 2S2P, with two panels pointing SE and the other two pointed SW. Since only one set will be at full power at any given time, you won't exceed the amp limit of your controller.

 

[Cussewago Rifleman]

So my original question was this:

I am making a small mobile 12 volt system mounted on a dolly.

I just wanted to know if using 1 ( I repeat, only 1 of these panels.). Would work With the components I listed.

 

[MichaelK]

Yes

 

[Rednecktek]

Yup, 1 panel on that SCC is a pretty perfect match for a 12v system.

 

[HRTKD]

I did something similar with my Board Build. I thought about going 24 volt but when the system isn't in use for camping I use it to keep the batteries in my side-by-side changed. 12 volt gives me more flexibility. If needed, I can run it off of a battery that is in a car.

I do use a 2s2p PV configuration, using 250 watt panels in an east-west orientation. Switching to two 445 watt panels would simplify my system a bit.