safe max wire voltage drop between PV and CC?

[Supervstech]

I agree.

OP, remember the rating of a charge controller is battery charging amps...
So you are limited to 35A OUTPUT.
You won't ever come close to 35A solar input with a 35A output controller.
So if you plan to utilize all the potential of your panels, you need a larger controller...
Adding a second controller means running a second set of PV cable to it...

 

[myersfamilyhome]

Ok, so with this setup it's cranking out power and all looks good except........ I had complete power failure at 3am on my battery bank I just put together due to what looks like 1 bad cell. I was hoping cell 15 would recover from being a little lower than the rest but I was wrong. I haven't started building my second bank so I'm thinking the easiest way to fix this is to swap the cell out with another when the rest of the bank gets to the same voltage. Is this correct? What do y'all think? I attached a screenshot of the Daly status page when it was charged and when it failed.

 

[justgary]

Did you top balance the cells?

 

[myersfamilyhome]

Did you top balance the cells?

I'm doing with the bms, haven't had enough sun since the build to bring up above 80% charge yet but getting there. It's starting to engage the active balance feature now.

 

[MisterSandals]

Victron SmartSolar 150/35

Just out of curiosity, what are your charge settings? Happen to have a screenshot?

haven't had enough sun since the build to bring up above 80% charge yet but getting there.

I'm not sure you've been over 50%.

 

[myersfamilyhome]

Today is a sunny day and CC is cranking out power ??. Here are my settings at the CC as well as the current status of the banks...that's right I went ahead and put the other bank together because the cells have been sitting in storage for awhile and wanted to apply what y'all are teaching me to both of them ?. Thank you all again for your help on this path.

 

[myersfamilyhome]

Today is a sunny day and CC is cranking out power ??. Here are my settings at the CC as well as the current status of the banks...that's right I went ahead and put the other bank together because the cells have been sitting in storage for awhile and wanted to apply what y'all are teaching me to both of them ?. Thank you all again for your help on this path. View attachment 123871View attachment 123872View attachment 123873View attachment 123874View attachment 123875

Small update: Balancing just engaged on the cells a couple minutes after the prior post

 

[MisterSandals]

Victron settings look great. Hopefully your cells behave well enough to all get to the 3.55V per cell (56.8V total). You have room to back that down a bit and still be 99% charged if your cells are not behaving.

Great work, keep us posted on how the balance goes when you get to your max (sun limited i know) today!

 

[myersfamilyhome]

It seems like once they hit about 52v charging slows down significantly. Is this normal?

 

[MisterSandals]

It seems like once they hit about 52v charging slows down significantly. Is this normal?

No, it should be full blast up to absorb voltage (or very close anyway).

Is your solar production close to this?

 

[myersfamilyhome]

No, it should be full blast up to absorb voltage (or very close anyway).

Is your solar production close to this?
View attachment 123895

 

[740GLE]

Ummmm is the sun setting ?‍

 

[MisterSandals]

Looks like its charging at 35A (your max setting you put in place). When you say it slows down, do you mean the voltage raises slower?

If so, that's the thing about LiFePO4, most of the capacity is between 3.2V and 3.4V so it only looks like it is slowing. You're filling 'er up, be patient.

 

[myersfamilyhome]

Sunrise: 7:30
Sunset: 4-4:30ish
Clear sky's right now

 

[740GLE]

Looks like its charging at 35A (your max setting you put in place). When you say it slows down, do you mean the voltage raises slower?

If so, that's the thing about LiFePO4, most of the capacity is between 3.2V and 3.4V so it only looks like it is slowing. You're filling 'er up, be patient.
View attachment 123899

That’s also the limit of the SCC, she’s earning her keep.