I am finding that the passive balancer in the BMS is draining of overly charged cells, and this cell drainage is not being fed back into the shunt, therefore the shut gives every increasing battery amp hours with each charge.
Anyone else come across this, any workaround ?
An amount of drift is normal.
Sounds as if the automatic synchronisation of the shunt to 100% isn't properly configured.
In the shunt settings check battery capacity, tail current, charged voltage, charge efficiency and Peukert.
Would help if you posted a screen shot of them and also gave battery details, particularly maker's charging recommendations
Passive balancing is wasteful of energy by nature.
This would be part of a batteries inefficiency at taking a charge. So needs to be factored into that part of the shunt setup.
