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Lithium OVERCHARGING!!

rvtyme

New Member
Joined
Feb 15, 2020
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I have new system which consists of:
Multiplus-II 12V 120 50AMP
Victron SCC
Victron Cerbo GX
Victron Smart Shunt
(3) SOK 206AH wired in parallel 12V

I had my trailer unplugged from shore power for a bit.. then plugged back in. The system seems to perform fine going from BULK to Absorption but seems to never go into float? The Multiplus seems to think that the voltage is lower and the Solar Charge Controller and Shunt are both reading 15.22V as well as the control panel for the trailer.

I reset the entire multiplus, upgraded firmware/software, reentered parameters for batteries (14.6 Absorption and 13.8 Float) - removed from the VE.BUS network and then reconnected... still no avail...
I have the multiplus connected. to the Bluetooth as well as cable to the cerbo gx. I'm stumped why this is happening. Hopefully something stupid I did!

Suggestions? See attachments (you can see the inverter is still charging way above the 14.6 max)



Screen Shot 2022-04-17 at 9.26.52 AM.pngScreen Shot 2022-04-17 at 9.26.52 AM.png

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I reset the entire multiplus, upgraded firmware/software, reentered parameters for batteries (14.6 Absorption and 13.8 Float)
Where did you get these numbers? Does SOK really recommend charging this high?

Do you have a screenshot of your charge settings?
 
OK now reset the Victron to 14.2 charge and 13.2 float. Minimal 5 to 20 minute absorption period.
Disable any equalization charge or reset the voltage to 14.3.
Disable any temperature compensation or set the index to zero.

No need to press the SOKs to absolute max voltage.

Nothing should be pushing the voltage to 15+ ever.
 
What does your multimeter say at the battery terminals vs. what the inverter and shunt report.
It's really odd that your shunt would not be the most accurate device in the system, as it should be.
Do any of the values change when the SCC is disconnected?
 
Where did you get these numbers? Does SOK really recommend charging this high?

Do you have a screenshot of your charge settings?
The vendor stated
Where did you get these numbers? Does SOK really recommend charging this high?

Do you have a screenshot of your charge settings?
Numbers were provided by the vendor via email and also posted on the website. Screen shot of my settings attached. One of the inverter setting and the other of the charger setting. What is concerning isn't so much the actual number - it is that the inverter when charging seems to think that the SOC is different than the solar charger or the Victron BMS. This is what made me remove it from the network and reconnect to the network to make sure these devices were all sharing. Also, the trailer monitor panel matches the SCC and Battery Monitor - just the Multiplus seems to think it is lower and continues to charge beyond what I have set in the configuration.
 

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OK now reset the Victron to 14.2 charge and 13.2 float. Minimal 5 to 20 minute absorption period.
Disable any equalization charge or reset the voltage to 14.3.
Disable any temperature compensation or set the index to zero.

No need to press the SOKs to absolute max voltage.

Nothing should be pushing the
What does your multimeter say at the battery terminals vs. what the inverter and shunt report.
It's really odd that your shunt would not be the most accurate device in the system, as it should be.
Do any of the values change when the SCC is disconnected?
 
I going to drop the charge to 14.2 and float to 13.2 see what happens as a test...
 
Update: Dropped the charge and float voltage and everything is looking normal. All battery measurements are in sync including the Multiplus-II. Not sure why this caused my issue but happen it looks like things are now working as they should. Thank you to all for your quick responses - Much appreciated!!
 
If you want to see how long the solar charge controller spent in each mode, go to the history tab in the Victron Connect app. When you see the bar graph for each day's production, click on a day. It will expand the bar graph and show you the time spent in each mode.

I don't know if this information is coming from just the solar charge controller or if the Cerbo GX is providing some of it also. Prior to installing my Cerbo GX I don't remember seeing this information, but I wasn't looking for it either. I was poking around today and stumbled upon it.
 
Also make sure you're using LFP battery settings so that temperature compensation is disabled. Since it SAID absorb and was 15.x volts, and your temp was 58 degrees, that makes me think temp compensation was active.
 
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