How do you wire a slave BMS unit?

If multiple Slave BMS units are used in series, care should be taken how to connect each. Two separate wires should be wired to the same cell: first wire for the lower Slave BMS unit as the end-cell voltage potential, and second wire as GND potential for the higher Slave BMS unit. See Fig. 7! Do not bypass the higher cell!

Why is the EMS subscription so expensive?

The EMS subscription is expensive (more than 1% of annual revenue). The EMS is causing downtime (EMS availability of less than 99% is detrimental). The EMS has cybersecurity concerns or is not addressing foreign equipment risks (e.g., cyber attack through the BMS).

What is a Master BMS unit?

Master BMS unit uses the same protocol to asynchronously send instruction messages and queries to all the Slave BMS units on the bus. After the Master BMS unit initial test, bus is scanned for Slave BMS devices. Each Slave BMS unit should have its own distinguished RS-485 address to prevent data collision and to be properly identified.

What happens when BMS master unit is turned on?

When the BMS Master unit is turned ON it commences the internal initialization procedure and searches the Slave BMS units on the RS-485 Slave bus. If no Slave BMS unit is detected or if a Master BMS unit detects different number of Slave BMS units than pre-programmed error 9 is signaled and the BMS stays in the Slave BMS detection mode.