Chins 400 AH Lithium BMS disconnecting because of momentary high voltage spikes

[Falling]

Hello,
I recently upgraded to a Chins 400 AH Smart Lithium from a Renogy 200 AH AGM. Now I am having trouble with temporary battery disconnects due to high voltage spikes.

Setup:
Battery- Chins Smart Lithium 400 AH.
Solar Charger- Smart Solar MPPT 100/50.
Solar Charger Settings- Default Lithium settings in the Victron Smart Solar
Monitoring- BMV 712 Smart
Monitoring- Chins App

Problem as I see- When a load comes on or drops off while getting full sun, I get a momentary spike in voltage. Typically the spike is around 15.1. The time length of the spike is hard to tell but I can tell it is long enough to trip the BMS. From Chin's app I can see that it disconnects the charge and discharge. The app shows them getting disconnected. Chins app will not allow me to adjust any of the BMS settings. After a few seconds the voltage drops back to normal and the battery restarts charging and discharging as normal.

I'm at a loss for what to do. Has anyone seen this problem. I can't imagine it's good for my electronics.

Thanks for any help.

 

[MisterSandals]

I'm at a loss for what to do. Has anyone seen this problem. I can't imagine it's good for my electronics.

I agree its probably very hard on the electronics.

I do not like the default victron settings. Not sure if that is your issue but you can easily set more sensible (conservative?) charge settings. It would be easy to see if this resolves your issue.

Are your loads by chance connected to the Victron load ports?

 

[mikefitz]

Lower the charge volts to 14.0 or even 13.8 until the battery stops entering protection mode.
Set the absorbtion period to two hours.
It's not the spike causing the Chins to shutdown, what is happening is due to cell inbalance, the BMS is shutting down the charge port. Energy in the controller causes the voltage spike.

Mike

 

[Falling]

Thanks for the response. I didn't think about the cell imbalance.

Loads are not connected to the victron load port.

I should set the absorption to 13.8 or the highest voltage that will not cause the issue and the time to 2 hours. Will this have an impact on reaching full charge?

Thanks again for helping.

 

[mikefitz]

13.8 volts will allow charging to full, or almost full 99%.
You have very useful data recorded by the Victron charger and smart shunt. This will allow you to see how things are progressing.
The Chins app may show battery and cell status, the cell volts will indicate the degree of cell voltage differences.
It will take some time for the cells to become better in balance.
Perhaps post a screen shot of the battery cell volts when it's near full charge or when it enters protection mode

 

[Falling]

@mikefitz

Thanks Mike. As you suggest I lowered absorption to 13.8V. I allowed the battery to get to 50% SOC then turned the solar on to recharge. During the recharge the battery was able to balance the cells properly. As you thought, the battery did not stop discharging. I repeated the experiment a few times and now, as you thought the cells are staying balanced better and the battery is not cutting off.

Thanks again Mike!