Design of a Thermal Battery Dummy with Integrated Sensor Node

High-performance Li-ion battery systems require sophisticated thermal management to ensure safe operation and long battery life. Testing such thermal management systems comes with some disadvantages and safety concerns. For this reason, the use of thermal battery dummies is advantageous. In this work, we present the design of a thermal battery dummy with 26650 cylindrical cell geometry with an integrated sensor node. The control of the heating power and the temperature measurement is done inside the dummy cell. Power supply and communication with a test bench computer are done through the supply lines. Thus, the only cell connections are the battery terminals, resulting in a dummy cell with geometric characteristics equivalent to a real Li-ion cylindrical cell. This and an addressing-based communication protocol allows parallel operation of multiple battery dummies in a dummy pack compound. The design of the thermal parameters is based on preceding thermal measurements on a real battery cell; in the following we explain the concept of the thermal dummy and go into more detail on the main electronic circuits. With final measurements on a prototype we show the achieved properties of the thermal dummy.