Community Forums

WV John · 11-10-2022, 08:45 AM

Quote:

Originally Posted by nvs4602

That SCC is just a cheap pmw scc. The idea is to Not use panels that aren't the same wattage together.

Good Scc to buy.

Victron
Renogy
Epever

Can you give the link for the 300W solar panels you bought?

Here are solar panels I bought:

https://www.amazon.com/dp/B0B8NNDRV9...roduct_details

theoldwizard · 11-10-2022, 08:54 AM

I STRONGLY recommend you purchase a clamp meter that can rad DC amps. Many different models available from about $50 to over $200.

UNI-T UT210E is pretty good.

nvs4602 · 11-10-2022, 09:09 AM

The bad news is those are only 100 watt panels. The physical size of them gives that away. 300W panels would be 60+ inches x 30+ inches. In size.

The good news is it makes it easier to hook them together. I would leave the factory installed panels as is on their own scc. I would connect these 3 panels together in series on your new scc so your output volts from panels combined would be around 60v. And your current will only be around 5 amps.

SteveJ. · 11-10-2022, 09:10 AM

Quote:

Wonder if I could series connect the 100 to the 300 and connect to the existing scc . and then connect the other 100 and 300 to a second scc ??

If you do that the 300 watt panel will be limited to 100 watts. Don't do that.

WV John · 11-10-2022, 01:24 PM

Quote:

Originally Posted by nvs4602

The bad news is those are only 100 watt panels. The physical size of them gives that away. 300W panels would be 60+ inches x 30+ inches. In size.

The good news is it makes it easier to hook them together. I would leave the factory installed panels as is on their own scc. I would connect these 3 panels together in series on your new scc so your output volts from panels combined would be around 60v. And your current will only be around 5 amps.

So as I have looked around and seen the various panels to vary pretty differently in size - and the Renogy higher watts panels are definitely bigger. As a result I reached out to the company that sold the panels I bought (on Amazon) and they assured me that these panels were 300W. Wonder if there is an easy/reliable way to "prove" 300w or not??

Since I have 1 300w in the back and one in the front just run cable from one to the other for series connection (probably 8 - 10 feet) won't lose too much juice??

WV John · 11-10-2022, 01:34 PM

Another potentially stupid question - but the cabling is already in place. 2 sets coming from the roof , but only one somewhat larger cable going from the electric panel inside the coach down to the battery compartment.

Is there a problem with connecting the "output" of BOTH scc's to the same cables going down to the batteries??

SteveJ. · 11-10-2022, 03:06 PM

Quote:

Originally Posted by WV John

Another potentially stupid question - but the cabling is already in place. 2 sets coming from the roof , but only one somewhat larger cable going from the electric panel inside the coach down to the battery compartment.

Is there a problem with connecting the "output" of BOTH scc's to the same cables going down to the batteries??

If you series up the 300's with each other and do the same with the 100's you can then hook those two strings in parallel to run down to the controller. A caveat, when hooking in parallel, the closer the voltage of the sets of panels, the better. Too much difference and the lower voltage set will pull the down the voltage of the higher set. If your voltages do not match up well you can run each string to it's own controller.

You indicated a significant voltage drop when you paralleled the 100 with the 300 so will want to have a separate controller for those panels, plus your current controller is quite under rated for your total panel setup.

Do keep in mind that for series hook ups, match the current. For parallel, match the voltage.

WV John · 11-10-2022, 08:58 PM

Quote:

Originally Posted by SteveJ.

If you series up the 300's with each other and do the same with the 100's you can then hook those two strings in parallel to run down to the controller. A caveat, when hooking in parallel, the closer the voltage of the sets of panels, the better. Too much difference and the lower voltage set will pull the down the voltage of the higher set. If your voltages do not match up well you can run each string to it's own controller.

You indicated a significant voltage drop when you paralleled the 100 with the 300 so will want to have a separate controller for those panels, plus your current controller is quite under rated for your total panel setup.

Do keep in mind that for series hook ups, match the current. For parallel, match the voltage.

Thank you

I assume it’s ok to connect the output of both scc’s to the same wires going down to the battery compartment ??

757driver · 11-11-2022, 10:19 AM

Quote:

Originally Posted by WV John

Thank you

I assume it’s ok to connect the output of both scc’s to the same wires going down to the battery compartment ??

Yes, as long as the current it is now carrying (from both scc’s) does not give a significant voltage drop. Do the calculation with a voltage drop calculator. Try to keep the voltage drop to 2% or less.

There would not be much use in properly harnessing all that energy from your solar panels just to loose a good portion of it from the scc’s down to the batteries due to an undersized cable.