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4.12. Balancing
The balancing of the cells consists in keeping the cell voltages homogeneous in all the system.
The resistive balancing management circuit is integrated into the SMU module: it partially
discharges any cells that exceed the specified voltage discrepancy with respect to their
neighbours via bypass resistors.
The balancing is done only if the cells are unbalanced (voltage difference more than 30mV) and
if their voltage is above 3.5V.
When the battery system is working, the balancing is done at battery level by SMUs
following BMM settings (overall cells voltages target) transmitted permanently via the
internal CAN bus. Balancing operates in all states when the BMM is power supplied.
During storage without BMM connected or with BMM powered-off, the balancing between
cells is ensured at module level by the SMU board. After long storage, there might inter-
module unbalanced that will be reduced as soon as the system is working.
4.13. Displayed information
N/A
4.14. Communication with application
For details, see document [RD1].
4.14.1.
Data sent by BMM to EMS
All data objects are readable by EMS using SDO management protocol (client / server).
But some of data objects are also transmitted periodically by BMM inside TPDO CAN open
frames (see document [RD1]).
TPDO frame interval is set at:
- TPDO1 = 100ms
- TPDO2 = 100ms
- TPDO3 = 100ms
- TPDO4 = 100ms