Battery systems for high voltages are comprised of a number of individual battery cells in order to reach system voltages of between 50 and 400 volts. The individual cells must be monitored separately by the battery management system to make use of the maximum available capacity of each cell and to guarantee safe operation.
For the monitoring of larger battery storages, Fraunhofer IIS is showing the flexible battery management system FlexBMS at embedded world (Hall 4, booth 460). A small electronic module at each cell detects cell parameters such as voltage and temperature. Optimized bus communication between these electronic modules minimizes the need for wiring between the cells.
The FlexBMS is also capable of precisely predicting the remaining capacity and the state-of-health by means of shunt- or resistance-based current measurements. This allows run time or range forecasts to be made, which eliminates the need for a safety buffer. The monitoring of any cell or module combination does not require any hardware adaptation. Furthermore, this flexible BMS can actively compensate for charge differences between the individual battery cells in order to always utilize the maximum capacity of the battery cells. For further information see www.iis.fraunhofer.de/batterymanagement