3.3. CAN Bus and RS485 / Modbus RTU Block
The CAN Bus communication channel is available on the J3: CAN connector. The RS485 / Modbus
RTU communication channel is available on the J4: RS485 / Modbus RTU connector.
These communication channels are isolated from the battery stack and share their common
reference with each other, with the general-purpose I/O, and with the specialized control inputs. A
120Ω bus termination is required on each end of the bus for these communication channels.
Termination is not provided within the Battery Controller on stock production units.
3.4. Power Supply, Current Shunt, and Contactor Drivers
Operating power, including primary power source for operating the contactor coils, is connected to
the Battery Controller at two connectors: positive to the J7: Current Shunt / +V Power connector, and
negative to the J6: Contactors / -V Power connector.
The current shunt, which is connected in series with the battery stack at the positive end,
connects its sense points to the Battery Controller at the J7: Current Shunt / +V Power connector.
Up to four system contactors may be connected and controlled by the Battery Controller,
connecting to the Battery Controller at the J6: Contactors / -V Power connector.
3.5. Mechanical Dimensions
The overall dimensions of the Battery Controller are 220mm X 125mm X 30mm. Extra space
should be provided around the module to allow for easy installation/maintenance.
Dimensions in the diagram below are shown in inches
The Battery Controller should be securely mounted in a vertical orientation, in an environment
that permits free movement of air through all ventilation slots for convection cooling. The Cell
Connections connector (J1) should be facing up or to the left. If it is to be used with a battery
chemistry such as lead-acid, which does not require balancing, the Battery Controller may be
mounted horizontally, with the ventilation slots oriented upwards. It is not advisable to mount the
Battery Controller on the underside of a horizontal surface.
The Nuvation BMS™ Low-Voltage Battery Controller weighs approximately 0.4kg.
Installation Guide - 2018-10-08, Rev. 2.0
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