A Forum run by Enthusiasts of MidNite Solar

General Category => System Design and Layout => Topic started by: keesh on July 29, 2025, 05:03:36 PM

Title: Why oh Why
Post by: keesh on July 29, 2025, 05:03:36 PM
I have 3 classics 250.  One master 2 slaves.  The blinky lights are showing they are wired properly.  However one of the slaves produces while the other does not.  See attached.  What did I do wrong?

TIA
Title: Re: Why oh Why
Post by: keesh on July 29, 2025, 05:15:11 PM
And now it works again.
Title: Re: Why oh Why
Post by: keesh on July 29, 2025, 05:26:00 PM
And now it is back at 16w
Title: Re: Why oh Why
Post by: ClassicCrazy on July 29, 2025, 09:20:12 PM
You don't seem to show any problem.
Your batteries are in Absorb so that means they are full.
If one controller has enough power to handle the load, there is no reason the other controllers are going to be charging.
The only way you will see the other controllers putting out power is to max out the loads on your system to be more than the power coming from the PV. Then if the voltage drops on the controller, they will start making power.
Larry
Title: Re: Why oh Why
Post by: keesh on July 30, 2025, 11:03:59 AM
Thank you.  That makes sense.  I thought floating meant the battery was full.
Title: Re: Why oh Why
Post by: ClassicCrazy on July 30, 2025, 12:03:10 PM
here is example of two of my batteries from yesterday.
As they approach the absorb the current input drops to zero .
My settings are 55.2v absorb 3.45v per cell and float 53.6v  3.35v /cell
The reason the first battery takes in more current when charging is because it is a 300ah battery and the second battery is 100 ah.
At float voltage the cells don't gain or lose any current as long as there is pv to supply loads. The current graph on here is only showing what is going into or out of the battery ( system amps )  and not showing the current being produced by controller
Larry
Title: Re: Why oh Why
Post by: keesh on July 30, 2025, 04:32:52 PM
What are you using to monitor current to the battery?
Title: Re: Why oh Why
Post by: ClassicCrazy on July 30, 2025, 08:42:41 PM
I have pace bms and am using Grahams github project
https://github.com/ClassicDIY/PylonToMQTT
See the wiki on that project for all the details.
So it works with the Pace BMS but since it is pylon based maybe it would work with pylontec type bms too ? Not sure on that.
I also have a Victron Smart shunt and that is via Bluetooth to Home Assistant . I wrote a yaml ( or rather maybe chat gpt did ? ) to output mqtt data from it to my existing raspberry pi that is getting all the bms data.
Larry