I tried to use Victron's Node-RED node "Battery Monitor". It delivers values for State of Charge and many other values correctly.
However, it outputs null when I select Measurement "Capacity (Ah)".
I can see the value in the Remote Console and it's also reported via MQTT:
N/c0619abcdef/battery/512/InstalledCapacity {"value":222}
Is it possible that there's a bug in that Victron node?