BMS Cell Board Manual
Description of Cell Board and Atlas ESS Operation

A BMS Cell Board is attached to every cell in the battery pack. When the cells are operating within their specified range the Cell Boards maintain a normally closed (NC) signal on the Cell Loop circuit.

The Cell Loop circuit is a single loop of wire that runs from cell board to cell board, then to the PLC and Data Logger, in a serial layout.

The PLC monitors the Cell Loop signal and connects the Atlas Energy Storage System (ESS) to the inverter or load by use of a high power relay called a contactor.

If any cell in the battery pack strays outside its normal operating range the PLC will disconnect the Atlas ESS from the inverter by opening the contactors. This prevents damage to the cells by removing the load on the cells.

The PLC provides additional outputs for inverters and auxiliary equipment. These outputs can used to prevent battery disconnect.

The BMS Cell Board monitors the voltage and temperature of the cell it is attached to. It also records events. Events occur when cell operating parameters transit through set points. Data and Events are stored on the cell board and transmitted to the Data Logger via the Cell Loop.

Each Cell Board is programmed with a unique identifying number. This number is marked on the Cell Board and displayed by the Data Logger. Cell Boards do not have to be installed in numerical sequence.

The Data Logger records and displays data while the PLC controls the Energy Storage System. The Data Logger does not control the ESS.

The Data Logger is an optional piece of equipment and is not required to operate the Atlas ESS.