I could really use some help getting my system parameters figured out. I am always going over voltage.

[rmaddy]

Batteries: 24v lithium ion, 202ah

You actually have LiFePO₄ 200Ah cells. While LiFePO₄ is a specific kind of Lithium-ion battery, it's important that you state that you have LiFePO4, not Lithium-ion.

Thanks for your reply! I'm not sure if you were aware, but I do indeed have two CCs. I have 4 panels connected to one and 2 connected to the other. You did make me think about something. I was under the impression when I bought the CC that it had a max voltage of 150v. I now realize that It's max is only 100v. My panels have a max voltage of about 30v which means that I am absolutely exceeding that on the one controller. Is there a way that I can connect my panels in two series groups of 3 panels going to each CC? I'm not sure if you can do odd numbers of panels in your array. I thought it had to be in even groups.

Having 4 of those panels on one 40A SCC and 2 on the other 40A SCC is just fine. But if the SCC has a 100V max input voltage then the 4 panels in series is very bad. I'd be surprised if you didn't already destroy the SCC. Those 4 panels need to be in a 2S2P configuration. You do not want to put 3 panels to each SCC since 3S is 90V which is too close to 100V since Voc goes up in colder temperatures. Though if you tell us the exact specs of the panels and the record lowest temperature where you live, we can confirm whether 3S on each SCC will work or not.

 

[73powerstroke]

Thanks for your reply! I'm not sure if you were aware, but I do indeed have two CCs. I have 4 panels connected to one and 2 connected to the other. You did make me think about something. I was under the impression when I bought the CC that it had a max voltage of 150v. I now realize that It's max is only 100v. My panels have a max voltage of about 30v which means that I am absolutely exceeding that on the one controller. Is there a way that I can connect my panels in two series groups of 3 panels going to each CC? I'm not sure if you can do odd numbers of panels in your array. I thought it had to be in even groups.

You can 2 in series and parallel them. And just 2 in series on the other charge controller. Maybe get 2 more panels. But it will be fine I think. Other people who have more experience will know.
I've definitely done it before. But that doesn't mean it's good lol

 

[Dynoman]

Thanks for your reply! Very informative. it's nice to hear from someone who has my specific model. Just to clarify, the settings you provided are for a 24v system, correct?

Yes the settings provided are used for my 24 volt system with Lifepo4 Cells. I am also using the Overkill Solar 8s 24 Volt 100 amp BMS. The cells you show in a later post with a picture and link show that you are using Lifepo4 cells so the settings listed should be a good starting point.

Have you preformed a Top Balance on your Lifepo4 cells prior to putting them into service?

 

[Eclipse11]

If you could take a photo of the spec tags of your solar panels, charge controller info, and battery bank layout then we could do the math and provide the proper setup. Usually charge controllers can handle a Max of 150v coming from your solar panels, different from your total watts. So if they are connected in such a way that exceeds the maximum volts accepted then this will cause the issue. Or if your battery bank is not properly connected to one another in a 12 or 24 v series, this can also be an issue. Battery terminals should be clean and tight. Your battery cables should be a thick enough gauge and the area where the inverter, batteries, and controller are should be in cool temperatures.