E. Oyarbide, L.A. Jiménez, P. Molina, R. Gálvez, C. Bernal: “Challenges of low-voltage energy storage for lifts”  5th Symposium on Lift and Escalator Technologies 2015, Northampton, UK, 2015

Here you have a link to the paper https://liftescalatorlibrary.org/paper_indexing/abstract_pages/00000079.html

And the video presentation: https://www.youtube.com/watch?v=umAMxy-TKr0&list=PLa5-w0efaxTG3W-A00Z7DD7ZfzsGtJAgw&index=6