In its work and research, the Battery System Technology Group covers the characterisation of cells, the development of battery modules and battery management systems as well as the use of storage systems in their operational environment. The scope of work includes:

  • Basic investigations of the electrochemical, electrical and mechanical behaviour of batteries
  • The development of dynamic behaviour models and the corresponding simulation environments
  • The development of algorithms and software for battery condition assessments, battery management, diagnosis, charge control and energy management
  • The dynamic, efficient and long-lasting use of batteries in mobile and stationary systems, and
  • The evaluation of battery application cases and cost development


Joaquin Klee Barillas
+49 (0)731 95 30-534

// The cell

Cells provide the basic unit in battery storage systems and are therefore characterised comprehensively and in detail in terms of their electrochemical, electrical, thermal and mechanical behaviour. They are analysed in regard to time and frequency (e.g. pulse measurements and electrochemical impedance spectroscopy). Our knowledge gained about the short-term dynamic behaviour of the cells and the long-term ageing effects is translated into mathematical, parameterised models and implemented in corresponding simulation environments.

In addition, our experience acquired about the behaviour of the cells is used for developing model-based algorithms for assessing the battery condition, forecasting the performance, energy and life cycles, and also for charge control.

Prismatic standard cell according DIN standard. Source: ZSW/ECP
Prismatic standard cell according DIN standard. Source: ZSW/ECP

// The battery module

The battery module is an assembly of individual cells and, together with a battery management system (BMS), it forms a functional unit to store electrical energy.

The work at the module level pays particular attention to the distribution of the cells in series-parallel assembly in terms of their charge and ageing status and to the corresponding depiction models and operational measures (e.g. cell balancing).

Algorithms, software and electronics for monitoring batteries, assessing the battery condition and diagnosing, forecasting and controlling charge are being developed for the BMS.

The prototypical and constructive work concerning battery modules encompasses the module construction, cell connectors, mechanical tension, sensors and cooling. Among other things, the work is used for demonstrating and evaluating the battery models (e.g. electrical behaviour models and heat flow models), battery management algorithms and also the operating and cooling strategies.

CAD drawing of the ECA battery module. Source: ZSW/ECA
CAD drawing of the ECA battery module. Source: ZSW/ECA

// The system

Batteries are used in very different application environments with very different demands in terms of the performance, energy and service life, for example as hybrid or traction batteries in electric vehicles or as Photovoltaics battery storage systems in buildings.

The primary task of the system technology is the model-based design and dimensioning of the storage system for its economical and reliable use for storing electrical energy. In regard to controlling, regulation and communication, the battery management system must be integrated in the energy management of the complete system. The aim of the battery system technology is to develop optimised and efficient operational strategies for the battery in interaction with the power electronics, measuring systems (e.g. smart meters) and dynamic loads as well as to ensure safe operation throughout the entire operating life.



a) Structure of a DC coupled PV-system, b) Structure of a AC coupled PV-system
a) Structure of a DC coupled PV-system, b) Structure of a AC coupled PV-system