New User, first question. Looking for feedback on the principal of connecting lithium batteries with built in BMS in parallel to form a bank, but within the bank having multiple BMS connections.
For example - 6 batteries in total rated at 100Ah each, bank capacity 600Ah
3 sets of 2 batteries within the bank ie 1 Master, 1 Slave at 200Ah x 3
3 BMS CAN connections, 1 from each Master to an Inverter
The batteries are DC coupled so in theory the Inverter has access to 600 Ah but only controls 200Ah. The inverters are not AC coupled so will be able to run independent AC loads.
My thinking is that the bank should sync together with regards to voltage and state of charge, assuming that to start with all batteries were more or less at the same starting point on an individual level. After that, each Master will work with the controller in the Inverter to charge/discharge as required. If one Inverter has more demand than another ie higher AC load for longer, then it can draw on the bank (6 batteries) for longer than it could if it was only connected to 200Ah (2 batteries).
As each mini-bank SOC changes then all three Inverters will create a level playing field or will the SOC end up being unbalanced? I am not familiar with how the internal BMS process works so perhaps someone could consider the above scenario and discuss with me.
For example - 6 batteries in total rated at 100Ah each, bank capacity 600Ah
3 sets of 2 batteries within the bank ie 1 Master, 1 Slave at 200Ah x 3
3 BMS CAN connections, 1 from each Master to an Inverter
The batteries are DC coupled so in theory the Inverter has access to 600 Ah but only controls 200Ah. The inverters are not AC coupled so will be able to run independent AC loads.
My thinking is that the bank should sync together with regards to voltage and state of charge, assuming that to start with all batteries were more or less at the same starting point on an individual level. After that, each Master will work with the controller in the Inverter to charge/discharge as required. If one Inverter has more demand than another ie higher AC load for longer, then it can draw on the bank (6 batteries) for longer than it could if it was only connected to 200Ah (2 batteries).
As each mini-bank SOC changes then all three Inverters will create a level playing field or will the SOC end up being unbalanced? I am not familiar with how the internal BMS process works so perhaps someone could consider the above scenario and discuss with me.
