Simulation app helps Volvo R&D test electric truck battery designs

On a computer screen, a battery pack can now be taken apart and rebuilt in minutes, with each weld checked before any metal is cut. That is the working image behind a simulation app built by Resolvent, a Danish engineering consultancy specialising in green energy, and now used by the R&D department at Volvo. The account here comes from an article sponsored by the software maker COMSOL, which supplied the modelling environment.

The problem is concrete. Delivery trucks cover long highway distances, and the battery packs in electric versions often fall short on lifetime for that kind of use. The LaserBATMAN project, which ran from May 2022 to May 2025, targeted two measures for battery packs: robustness and lifetime. One step that touches both is laser welding, used to join battery cells to a busbar, the metal strip that links them in a pack. Welding done correctly can help battery life; done incorrectly, it can increase the risk of degradation. Computational modelling was the team's way to predict these effects at each manufacturing stage.

The team started by studying how welding affects the electrochemistry of individual cells. Their ambitions grew: they modelled performance from cell to pack, then turned the model into a design tool. They first built an electrochemical model of one cell from the chemical reaction equations, fed it input data, and used the outputs to train a deep neural network, a simplified model that gives quick insight into cell behaviour. The app sits on top of that trained model. Users enter the pack geometry, the number of cells, the ambient temperature and charge–discharge profiles, then see how the battery performs. A "Busbar Weld Design Tool" inside the app lets users vary weld shape, busbar thickness and laser penetration depth, and test what happens in production if a weld does not reach far enough into the busbar. A "Compute Battery" function reports the weld temperature, the state of charge and the thickness of the solid–electrolyte interface layer, and can show whether cooling airflow creates turbulence or stagnant air.

For fleet operators, the stake is the one the trucks already face on the road: a pack that lasts long enough for highway routes. The app's immediate users are engineers, not drivers. It lets Volvo's R&D team test weld and cooling choices before committing to them, and Resolvent's team says it can trade cooling against pack size. In one example they describe, better cooling could allow the design to drop two battery cells while keeping the same performance. That is a projection from the model, not a measured result on a truck, and the article offers no field data or production timeline to confirm it. What the project does show is a method: the welding step, long treated as a manufacturing detail, is now modelled alongside cell chemistry and cooling as part of the same design question.