The Lithium Ion Batteries for Electric vehicles need to be managed, otherwise they would deteriorate like those in Mobile phones. The Battery Management System is designed to do just that.
Different manufacturers use different approaches to Battery management, but the objective is to prolong the life of the battery. The main concern is when charging approaches 100% charge, as too long at 100% degrades the battery. To reduce degradation the system ‘Ramps down’ the charging rate, consequently after around 80% charge the battery charges at a much slower rate.
Understanding how charging rate varies over the time plugged in
How do they work?
Unless a full charge is required it’s better for the battery not to charge past 80%. Consequently, although 0 to 100% charging times may be accurate they may not be helpful.