Operating Instructions

January 8, 2021
BMS-1001-TH BMS
12
SYSTEM CONNECTION ARRANGEMENT
A site analysis should be performed when deploying a BMS system to ensure that all cells within a
baery bank are adequately monitored, and the input rang of each individual BMS is not exceed.
For example, the typical lead-acid baery bank used for generator start-up is comprised of 96 series-
connected cells with a nominal oat voltage of 2.70 VDC and an absolute minimum (discharged)
voltage of 1.80 VDC. To monitor the enre baery system, 10 BMS' are required:
1. 8 × BMS' are each connected to 10 cells (80 cells total). Each analog input will vary between 1.80
VDC and 2.70 VDC, and the total voltage applied to the BMS is between 18.00 VDC and 27.00 VDC.
2. 2 × BMS' are each connected to 8 cells (16 cells total). Each analog input will vary between 1.80
VDC and 2.70 VDC, and the total voltage applied to the BMS is between 14.40 VDC and 21.60 VDC.
Other wiring arrangements are possible. For assistance in determining the connecon scheme for a
parcular installaon, please contact Electronics4All.
In addion to serving as an analog input, baery cell connecons 0 and 10 are the main input power
connecons to the BMS. When less than 10 baery cells are connected to an individual BMS, the cells
should always be wired from boom (lowest potenal) to top (highest potenal), and the unconnected
cells inputs should be shorted to the highest potenal in the baery bank being monitored.
Connecons that serve as power inputs to the BMS should be protected by an external
circuit breaker or emergency disconnect switch. The circuit breaker or disconnect must
interrupt both conductors simultaneously, be suitably located and easily reached, and be
marked as the disconnecng means for the BMS.