Distributed Battery Monitoring with Contactless Communication
The battery system is still the most expensive element in today's electric vehicles. The novel distributed battery cell monitoring and management concept developed by Fraunhofer IISB allows a significant reduction of the final battery pack costs. Further, due to economies of scale, it provides reduced development costs and much lower time-to-market.
The proposed concept provides a contactless cost-efficient data transmission interface with capacitive coupling, thus making the development of a battery monitoring circuit for each type of battery module needless. The smart battery cells integrate all the sensors of the monitoring electronics together with passive cell balancing and cell heating functions.
The advantages of distributed battery cell monitoring are:
- The monitoring and balancing functions are integrated on each smart battery cell, thus improving the reliability, the assembling, and contacting efforts.
- The printed resistor used for passive cell balancing integrated onto the battery cell can be additionally used for heating the cell in winter conditions.
- Smart battery cells enable much shorter time-to-market when developing novel battery packs, since no more complex application specific battery monitoring circuits and boards need to be developed.
- The modularity and flexibility of the usage of the smart battery cells is greatly improved.
- The hardware of the battery management system can be standardized and reused in new and different developments by improving only the software part.
- The smart battery cells provide all the necessary integrated electronics to be monitored.
- The electronics integrated into the smart battery cells allows protection against counterfeit.
- The cell voltage, temperature, pressure, and balancing current can be measured by the monitoring electronics and sent to the BMS without any additional contacting effort needed when constructing the battery module.