Solar charge controller with Maximum of 300 W, how much panel can I attach?

[Tenukitime]

Hi all, I'm building some solar powered remote surveillance systems. This is my first time messing with off-grid solar, and I've learned a lot from these forums.

One thing I can't quite figure out: can I oversize my solar panel to the charge controller?

I'm using a Linovision POE-SW805G5U-Solar switch as the basis for my build. It is a 5-port network switch with a built-in solar charge controller. It has PoE out ports that will power the cellular router and the camera equipment. Seems pretty great as everything will be 24v, no need for an inverter, very few wires. I've got it running on shore power at my house now to get a baseline for power consumption, but I think I'm going to want as much as I can get. If I need to run a separate charge controller, I will do that, but if I can maximize the power output from this one, that might simplify things even more.

The charge controller states that it has a Max of 300W. So my question is, can I do a solar panel greater than 300W, and it will only provide 300W of power through the charge controller? Or if I hook it up to a 380W panel, will it blow the charge controller?

Thanks for any input!

 

[sunshine_eggo]

https://linovision.com/cdn/shop/files/POE-SW805G5U-Solar_datasheet.pdf?v=13283748041541749645

The charge controller states that it has a Max of 300W. So my question is, can I do a solar panel greater than 300W, and it will only provide 300W of power through the charge controller? Or if I hook it up to a 380W panel, will it blow the charge controller?

IMHO, no. It's a PWM controller. I would respect all limits without exception. Stick with 36 cell panels if using 12V and 60 or lower voltage 72 cell panels if 24V.

 

[Rednecktek]

Looking at the data sheet, on a 24v system the max PVInput is 45v which limits you quite a bit on panels. That's going to be your biggest limitation. In reality, being as this is going to be out in the weather I would call your max input to be 36-ish, but with that being a PWM controller, 30v Vmp panels would be perfect.

So, assuming you can find panels in that 36v VoC/ 30v Vmp range, you can feed it all the watts you want (within reason, an extra 20% is generally fine) and it's only going to be able to utilize 300w, so anything over that will be gravy and really help in the lower light conditions like winter, spring, and fall.

 

[sunshine_eggo]

Looking at the data sheet, on a 24v system the max PVInput is 45v which limits you quite a bit on panels. That's going to be your biggest limitation. In reality, being as this is going to be out in the weather I would call your max input to be 36-ish, but with that being a PWM controller, 30v Vmp panels would be perfect.

So, assuming you can find panels in that 36v VoC/ 30v Vmp range, you can feed it all the watts you want (within reason, an extra 20% is generally fine) and it's only going to be able to utilize 300w, so anything over that will be gravy and really help in the lower light conditions like winter, spring, and fall.

I disagree. You can't over-panel PWM safely.

 

[Rednecktek]

I disagree. You can't over-panel PWM safely.

In that case, the 5a limits you. I can't think of a way to get 300w out of 5a and 45v limits. A stand alone MPPT controller and ignoring the built in controller is probably the best option.