Modelling

The modelling of any battery pack will cover the electrical-thermal performance attributes of the cells. This mathematical modelling is likely to initially be a simple spreadsheet based model, then over time as the data and requirements mature so will the model.

Battery Cell Modelling

By conducting experiments to measure the battery voltage at various SoCs and temperatures it is possible to develop phenomenological models that relate the applied current and the voltage. An equivalent circuit model (ECM) is one such phenomenological model most widely used in industry to simulate the voltage response for subsequent Battery Management System control and state estimation.

digital twin poster

Digital Twin of a Battery Module

The capacity and resistance differences of cells amplify the inhomogeneity at a system level and results in accelerated aging and degradation.

For the module design, where many cells are in parallel, the BMS typically does not have access to individual cell currents and temperatures.

We aim to predict current, state of health and temperature of each cell in the module (or pack) via modelling the interaction between cell and busbar and weld quality.

Modelling Software

There are lots of packages available to model the electrochemistry, cell, module and pack level at electrical, thermal, mechanical, safety, control and even at the atomistic electrochemical level. We have listed the different packages available in a table so that you can search, sort and download it.

Tesla fast charge thermal model building on open source data and a siemens model

Tesla Model 3 Fast Charge Model

Building on the Tesla fast charge thermal model that was discussed in the Siemens post: Race to the clouds: Battery thermal behavior simulation of a Tesla Model 3.

This article looks at the cooling system and impact of a change in cooling direction. Starting with the model and the original Fast Charge Scenario.