For my internship I had the opportunity to spend three months at TRATON in Sweden, near Stockholm. During this period, I investigated aging in lithium-ion batteries for electric trucks using equivalent circuit models and equivalent hydraulic models, with the goal of estimating battery degradation from operational data. Both my company and university supervisors provided excellent guidance through weekly meetings, which gave me valuable insight into research and development within an international industrial environment. During my stay I also experienced life in Sweden outside of work. I enjoyed the surrounding nature a lot, which is remarkably accessible even near a major city like Stockholm, and experienced cultural aspects such as “fika”, which some Swedish coworkers treated as nearly holy. As part of my time in Sweden, I also travelled further north during winter to see the northern lights and take part in activities such as snowmobiling. Overall, I had an excellent experience in Sweden, both professionally and personally. The support from Stichting 3E helped make this stay possible by contributing to the higher costs of accommodation and living abroad.