DEYE 5KW hybrid inverter going past set absorption voltage ? HELP

[gonmag8]

Hi all,
I have connected my 17s 280Ah lifepo4 battery to my deye 5kw inverter this week.
Today its the first time I am being able to fully charge it due to cloudy days.

The inverter is going past the battery set voltages and I cant figure out why.
On the Battery settings page I have it set to use battery voltage.
Then for voltage I have:
Float 57.2v
Absorption 58v
Equalization is at 57.6 but zero hours as I want it turned off.

The sun came out and the inverter is now charging at 58.5v (displayed on the inverter itself) and triggering the JK BMS cell overvoltage protection

has anyone witnessed this ? is there any other config that I am missing ?

Thanks for your help.

 

[sunshine_eggo]

Do you really have a 17S LFP battery?

Do you have a temperature sensor on the DEYE? Is temperature compensation enabled?

If it's < 25°C and temperature compensation is enabled (should only be used wit lead acid batteries), charge voltage will be HIGHER than the set voltage.

 

[gonmag8]

Yes, 17s.
No sensor, and temperature is about 18 degC but the battery temperature sensor isnt connected.

Temperature compensation is a good call.
It is set as per default
mV/C/Cell is set to -5
Not sure how to interpret that since the inverter has no information about the number of cells?

The good news is that It seemed to have stopped at 58.5v.
Somehow there is a 0.5v deviation.
I have set it to 57.5 now and it seems to go to 58 and stop there.
Its weird but seems to have a deviation, I can work around it.

 

[gonmag8]

I am going to set temp compensation to 0 and see if the delta goes away.

Thanks, greatly appreciated ?

 

[sunshine_eggo]

-5mV/cell/°C would put you at +0.8V @ 18°C

In any case, I wouldn't get too worried about it. 58.5V @ 17S is only 3.44V/cell, and that's a very conservative charge voltage.

 

[Tanishq]

Set voltage compensation to 0mv/c and calibrate BMS voltage from the app.