Question for the solar guys

epretot · September 29, 2023, 06:07:46 PM

Quote from: windtrader on September 28, 2023, 06:49:30 PM
i saw this and it seems similar to your situation. I did reread this thread and don't have any new thoughts on the matter.

https://diysolarforum.com/threads/mysterious-battery-voltage-spikes.69989/

Thanks. I read through that and did learn a bit more.

I suppose the imbalance really has a major affect on the system.

I'm going to see that solution through before exploring anything else. It makes sense that the problem is occurring more often as the batteries get further out of balance.

In other words, installing the balancer and letting it work its magic.

windtrader · September 29, 2023, 08:55:48 PM

Not sure what battery config you have but in general good lithium batteries shouldn't get out of balance but a very small amount. Not sure how much a balancer is but I'd just top balance each first and see if the problem exists. If it still occurs then paying for more electronics won't fix it

freds · October 01, 2023, 05:20:44 PM

Well since you have mostly Victron equipment you can try their forum...

In the Victron App does both the Solar controller and Quatro show the same battery voltage?

I had a problem with my system last year and the ground connection was corroded for my solar chargers..

epretot · October 01, 2023, 05:25:00 PM

Quote from: freds on October 01, 2023, 05:20:44 PM
Well since you have mostly Victron equipment you can try their forum...

In the Victron App does both the Solar controller and Quatro show the same battery voltage?

I had a problem with my system last year and the ground connection was corroded for my solar chargers..

Yes. I'm a member there. My thread was buried on page 4 in under an hour...

I was able to put a volt meter on the charge controller this morning during the glitch. I had 65-70 Volts coming in from each array and the battery voltage was between 28.6 and 30. Bounced up and down for a few minutes then rested at 28.80.

The quattro is consistent with what the BMV is reporting.

freds · October 02, 2023, 08:16:09 AM

Quote from: epretot on October 01, 2023, 05:25:00 PM
Yes. I'm a member there. My thread was buried on page 4 in under an hour...

I was able to put a volt meter on the charge controller this morning during the glitch. I had 65-70 Volts coming in from each array and the battery voltage was between 28.6 and 30. Bounced up and down for a few minutes then rested at 28.80.

The quattro is consistent with what the BMV is reporting.

Weird, how about selecting custom battery in the charge controller's setting and set the maximum voltage to say 27.5?

Then if it exceeds that you have a defective charge controller. You said arrays so I assume you have two controllers?

I recently converted my system to Rpi 4/Venus OS controller and now have a surplus CCGX device that I will be selling, you could then implement DVCC which would bring the charge controllers under automatic external control.

Going to post on my build thread about that implementation soon.

epretot · October 02, 2023, 06:04:13 PM

I believe the controllers are technically doing their job.

There are some pretty strong opinions about the battery imbalance causing this.

I did find one thread that mentioned something about the their controller needing time to adjust to early morning light. They would get an over-voltage first thing until the controller "regulated".

With regards to the CCGX, I need to watch those channels you posted. It's on the list.

I haven't added much to my build thread, but I have been so busy working on it I haven't had time to explore more solar knowledge.

epretot · October 27, 2023, 06:14:34 PM

Update:

I charged each battery individually and installed the victron battery balancer.

I've gone nearly a week without a voltage spike. I also installed the secondary monitor of the smart shunt to monitor midpoint voltage deviation.

Seems as though it was the fix.

windtrader · October 27, 2023, 07:42:47 PM

Quote from: epretot on October 27, 2023, 06:14:34 PM
Update:

I charged each battery individually and installed the victron battery balancer.

I've gone nearly a week without a voltage spike. I also installed the secondary monitor of the smart shunt to monitor midpoint voltage deviation.

Seems as though it was the fix.

The problem was out of balance batteries? Had you not top balanced them before?

freds · October 28, 2023, 04:03:55 PM

Quote from: epretot on October 27, 2023, 06:14:34 PM
Update:

I charged each battery individually and installed the victron battery balancer.

I've gone nearly a week without a voltage spike. I also installed the secondary monitor of the smart shunt to monitor midpoint voltage deviation.

Seems as though it was the fix.

Great to hear that you tracked down the problem and fixed it!!!

epretot · October 29, 2023, 06:37:02 AM

@ Windtrader

It appears that was indeed the problem.

No, I didn't. But lesson learned.

What I did do was check their voltages. They were close. I assumed that was good enough. Clearly it was not.

Quote from: freds on October 28, 2023, 04:03:55 PM
Great to hear that you tracked down the problem and fixed it!!!

Thanks. I'm amazed at how a small deviation csn cause so many issues. I guess that's the "nature" of these batteries.

epretot · November 06, 2023, 04:46:10 PM

So after installing the battery balancer, I now get a deviation alaem in the morning as the sun hits the panel.

I originally got a voltage spike and disconnect at this time of the morning.

I have also noticed this all occurs at a 100% SOC. If shore power is off, and the batteries are paetially discharged, none of these issues occur.

At least that's my observation.

I'm wondering if one of the charge controllers is the culprit.

freds · November 07, 2023, 08:06:39 AM

Quote from: epretot on November 06, 2023, 04:46:10 PM
So after installing the battery balancer, I now get a deviation alaem in the morning as the sun hits the panel.

I originally got a voltage spike and disconnect at this time of the morning.

I have also noticed this all occurs at a 100% SOC. If shore power is off, and the batteries are paetially discharged, none of these issues occur.

At least that's my observation.

I'm wondering if one of the charge controllers is the culprit.

Well this still sounds strange!!!!

But what batteries are you using? Are they bluetooth and can they have their firmware updated?
Maybe disable one of the charge controllers to find out which one is causing the problem.
Load a custom profile into both charge controllers that limit the maximum voltage it will charge too and back off a volt.
Get a GX computer and implement DVCC that way it will always control charging.
Leave something on like a refrigerator so it is always working from a deficit in the morning when the sun comes up.

epretot · January 20, 2024, 05:42:56 PM

The saga continues...

Here is a screen shot of my mid point deviation. It's jumping all over the place.

It is extremely cold here and the deviation became worse as it got colder.

What's weird is (and you can see by the graph) the deviation can go from .10 to 2 or 3 and back again in a moment. In fact, the voltage bounces around every second. How can that be?

I haven't tested it with a meter yet, but when the arctic blast leaves I will.

Any thoughts?