“Energy storage systems for vehicles are extremely interesting, because they are so complex and there are so many disciplines that need to work together to design such systems,” says Susanne Bjärsvik, Director Energy Storage System, at Volvo Group.
She has worked with batteries for 12 years and was a pioneer in the field when she and her team developed the battery for Volvo Cars’ first plug-in hybrid car. Now that she is leading the team for energy storage systems at Volvo Group, there are even more challenges. To start with, there is a wide range of vehicles that are being electrified; buses, trucks, construction equipment, boats and industrial applications. They all have different needs.
Reducing weight is one prioritized area. Batteries for large vehicles are still very heavy. They can weigh approximately 500 kilos and a truck has on an average six of these. Range is obviously also an important area, and more range adds more weight.
A truck battery has thousands of lithium-ion cells and with six of those batteries, you have a great number of cells that need monitoring to secure performance and life length.
The li-ion cells are a little bit like babies. You need to protect them from impacts, heat and cold – and they prefer a temperature of around 25-30°C. You have to give them the right conditions, so they last as long as possible with good performance.
The batteries have control systems on different levels, to optimize their performance according to the customers’ needs. One advantage Volvo Group has, compared to those developing batteries for passenger cars, is that they have a lot of information about the customers – what routes they operate, where they want to charge their batteries, the temperatures and topography of their routes and much more – so that they can calibrate the software to optimize the life-span and performance of the batteries.
“The development of the control systems is really exciting, and we’ll see more use of machine learning and artificial intelligence in this field in the future,” adds Susanne Bjärsvik.