Upgrade to Victron or other?

[Gibson]

Hello to the group!

I have had my test run solar system running for about 6 months now and am wanting to up the game a little. Part of that is upping from 200ah to 400ah and an eventually 6 by end of the year. 800ah is really where I need to be but right now am finding it hard to justify for what I am using it for.

Besides adding a few more batteries I am going to add another two panels now and then another two by the end of summer for a total of 1kw.

Current Spcs at 12v sytesm:
Epever Tracer 4215BN with the MT50 interface.
GoWise 3000 watt inverter.
Battle Born 100ah x 2
Rich 100 watt panels x 6 in series parallel. (3x3)

I am considering upping to a Victron, undecided on what model would be best for my needs without overspending. I thought read somewhere that the battery connection points on the Victron panel are kinda tiny. I am running #2 welding wire from the charge controller to the point of connection at the inverter, about 6" of wire. Will the Victron take that size wire? I hate to cut a bunch of strands off to thin it out. I am open to other mfr.s besides Victron. Morningstar? Who else?

Thanks...just got called to dinner and it's Taco night. Gotta go. LOL

 

[rmaddy]

Rich 100 watt panels x 6 in series parallel. (3x3)

FYI - 6 panels would have to be either 2S3P or 3S2P. 3S3P is 9 panels.

I am running #2 welding wire from the charge controller

From what I can tell that is a 40A charge controller. You only need 6AWG (even 8AWG). Why 2AWG?

10 100W panels is of course 1kW. 1kW / 12V = 83A of possible charge current. That's getting into more expensive charge controllers. The price goes up with amps. You could use two SCCs, each with 5 panels. But 5 panels is a pain because it either needs to be 5S or 5P. 5S could work depending on the Voc of the panels and your temperatures. Maybe put 6 panels on one and 4 on another.

Going to a 24V system could be better. Then you only have about 41A of charge current. You could keep your current charge controller. But you would need a new inverter (but 3000W on a 24V system is better than on a 12V system).

 

[Gibson]

I do not have the lingo down.....what I have are 6 panels in what I would call two banks of 3 panels each. Each bank is connected in series and then the two banks are connected in parallel. I attached the system I sketched out when I put it together.

Why 2awg? Because I have #2 welding wire on hand but no 6 or 8.

Perhaps I have it wrong...but if each panel is 5.41amp, 18.5 volts, the max the solar charger would see is 54 amps with 10 panels so the charge controller would need to be 55 or 60. No?

I am not going to switch to 24v, not for what I am doing.

 

[rmaddy]

what I have are 6 panels in what I would call two banks of 3 panels each. Each bank is connected in series and then the two banks are connected in parallel.

That is 3S2P - 3 in series, 3 more in series. Those two strings connected in parallel.

Why 2awg? Because I have #2 welding wire on hand but no 6 or 8.

Larger wire is fine as long as it physically fits. You do not want to force oversized wire into terminals that are not big enough for it.

Perhaps I have it wrong...but if each panel is 5.41amp, 18.5 volts, the max the solar charger would see is 54 amps with 10 panels so the charge controller would need to be 55 or 60. No?

The main amp rating of a charge controller is its battery charge current output, not the input from the panels. A 40A charge controller means it can output up to 40A of charge current to the battery. Some controllers do specify a max PV input current as well. Check the spec sheet.

A 40A charge controller on a 12V system means the controller can make use of 40A x 12V = 480W of solar. If you have more panels than that then the controller won't be able to make use of the extra potential. Let's say you put 600W of panels on such a controller. The extra panels mean you could get more power earlier and later in the day than if you just had 480W of panels. But midday when the panels might be able to produce the full 600W, the controller will still only use about 480W. This is fine if it meets your needs.

In your case you are planning on 1kW on a 12V system. As I showed, 1000W / 12V is about 83A. That's the potential battery charge current output you could make use of. Using a 1000W of panels with a 40A controller would be a giant waste of potential power unless you have a lot of shading issues.

 

[HRTKD]

My Victron 100/50 MPPT is spec'd for 6 awg cable and that's what I used. I would rather buy different cable than some other brand of solar charge controller.

2 awg is overkill. But if you're dead set on using it, the Victron 250/60 is spec'd for 2 awg cable on the battery side. However, once you see the price of that MPPT, you'll see how much less it will cost you to buy some 6 awg cable.

 

[Gibson]

Some controllers do specify a max PV input current as well. Check the spec sheet. The manual mentions 1540 max PV input.

A 40A charge controller on a 12V system means the controller can make use of 40A x 12V = 480W. I see. That adds some clarity. I guess one of the things that has always puzzled me is what is best to provide the to MPPT controller..volts or amps. It would seem that watts are, and then CC will take that and convert it to what it needs?

Definitely need to move my array though. I put it up quick and easy as cold weather was setting in and so where it is it remains in the shadows until noon. I have plenty of opportunity to make sure it gets sun dusk till dawn.



Thanks for the input HRTKD. I think what I am looking at is a 150/70 or 85 to make use of 1kw. I am not apposed to buying some #6. I just hate to throw away the cable connectors. They where pretty scarce when I put this together and had to go to three places.