Hi Guys, i have a Axpert 5.0K+ with 2x Pylontech US2000's as a home backup system. the batteries have a age difference of about 20 cycles (Zero ALM state).
I also have the axpert to Pylontech cable to interface the inverter and battery stack properly. this worked well with one battery, the charge parameters where set up automatically and had no issues. once i added the second battery i did a few test runs and noticed that the charge current ramped up to 50 A witch is right for the stack. However, i noticed that the fan ramps up and down all the time... If i check the charge current it hops between 20A and 50 A every 60 seconds or so. i havent timed it but it seems to be round 60 seconds 50 A then 15 - 30 seconds 20A and so forth..... is this normal behavior from the inverter and is this healthy for the battery stack? as i understand lithium wants CV CA witch this is not.... the charge voltage changes from 51,4v to 50,2v when it goes from 50A to 20A. Iv confirmed the values and observed the battery stack and the inverter using battery view and MultiSIB control. they all checked out to be the same as the display.
Could i possibly be needing a firmware upgrade on the inverter? iv never done one from new. i can confirm that the pylon's are running the same firmware.