We have the following settings in the Lynx Smart BMS:
The current drops all the way down to 0 A, in other words well below the tail current threshold. The voltage stays above the “Charged voltage”, and this condition lasts for hours. Still, the SoC never gets reset to 100 %. Is this a bug?
I don’t know nothing about the Lynx BMS. The current may probably drop to zero because your charge voltage is set too low. Which kind of battery do you have? 15s? 16s? For a 16s battery you should set the charge voltage to 55.2V (3.45 V per cell)
@TomBerger The charged voltage is the voltage that has to be exceeded to synchronise to zero, not the charging voltage. Look at the graph, the charging voltage is 55.05V.
@skagmo I am not sure what your problem is, with the Lynx BMS the charging voltage should have dropped to float rather than staying high if the Lynx BMS is controlling the charge via DVCC. The only thing that I can think of is if the voltage has not fallen below 53.8V so that the synchronisation logic does not get reset.
The charger behaves like it should. The issue is related to the SoC estimator in the BMS.
The problem is that SoC is not set to 100 %, but stays at ~90 % even though all criteria for SoC synchronization are fulfilled.
You are suggesting that the “Charged voltage” (set to 53.8 V) acts as a falling edge trigger? That’s not my impression from the description in the manual, which indicates it is a lower threshold:
Charged voltage: the voltage at above which the battery monitor synchronises and resets the SoC to 100%. For synchronisation to happen, the tail current and charged detection time conditions need to have been met as well. The default is set to 14.0V and can be adjusted if necessary. In case the system voltage setting is changed, the charged voltage setting needs to be adjusted as well.
I know how the charged voltage is meant to work, voltage needs to go above 53.8V which is why your data are odd.
What I am questioning is in your graph of charging voltage and current, the graph starts above 53.8V, so I was just wondering if the logic requires the voltage to START below 53.8V for it to cross over, if it stays above perhaps it does not work.
Only other suggestions are complete system shutdown and restart or possibly update firmware.
What battery bank is connected? This looks a bit like behavior seen elsewhere when trying to use the Lynx Smart BMS in “test loop” mode on non-Victron batteries.
