I maybe found a possible cause and it is VE.Bus System - Charge voltage setpoint.
It is probably send by BMS, bacause on other systems it is different or even changing almost every minute (JBD).
On JK Charging voltage setpoint is set at 0.4V higher than CVL. It changes with float from BMS and is again 0.4V higher.
Victron then limits charging voltage not to the CVL from battery but to “Charging voltage setpoint”.
JK:
Battery CVL (float test): 54.8V
VE.Bus System - Charge voltage setpoint: 55.20V
CVL < Charge v. setpoint
Difference MINUS -0.4V
Battery CVL: 53.2V
VE.Bus System - Charge voltage setpoint: 52.80V
CVL > Charge v. setpoint
Difference PLUS 0.4V
Based on victrons guide. It should be set lower than CVL.
• Charge Stages:
Most Victron chargers go through different charge stages, including bulk, absorption, and float.
• Absorption Phase:
During absorption, the charger applies a constant voltage (the “charge voltage setpoint”) to the battery, allowing the battery to reach its full capacity.
• Float Phase:
Once the battery reaches the charge voltage setpoint, the charger switches to float mode, maintaining a lower voltage to keep the battery topped off without overcharging.
• Setting the Value:
The “charged voltage” setting in Victron devices is often used to calibrate the battery monitor as full, and it should be set slightly below the target absorption voltage (e.g., 0.2V less).
• Importance:
Proper configuration of the charge voltage setpoint is essential for battery health and longevity.
• Examples:
• For a 12V battery, the recommended absorption voltage might be 14.4V, and the charged voltage setpoint in a battery monitor would be 14.2V.
• For a 24V battery, the corresponding values would be 28.8V and 28.4V
Also discussed by me with more data in this thread from 27.6.2025 - Ignores discharge power to float voltage - #82 by k3ivi
I have send this issue to JK RnD engineers. Hope it can and will be fixed.