Lithium Battery Internal Bluetooth Monitoring

Gomers2

Just a heads up regarding the built-in Bluetooth monitoring features provided on some of the newer lithium batteries. I am learning that the raw voltage measurement provided by the internal BMS, via bluetooth, is accurate. However, it seems that the coulomb accounting is not necessarily accurate. I have experienced this phenomenon and did some research which indicates that the victron smartshunt (or a similar external shunt) is far more accurate than the internal Ah counting mechanisms in the batteries. Apparently they do not do well with microdraws, and sometimes "fall asleep" or get stuck on previous read out levels. So I'm using the Bluetooth provided from the battery as a secondary measure of raw voltage. It is identical to what the smart shows and it seems very accurate. And I assume the temperature measurement and the cell balancing data is accurate as well. But in terms of the SOC, it seems an external smart shunt is by far the more reliable measure.