It's not charging to to a particular %.
When the battery is new, it should be 100% health.
Status is how much of the battery has been used since being charged.
My battery, for example, was 100% health when new. Meaning my range would show up as 100km on eco.
My battery is now at 92%...
I just noticed the other day my range was 89km after a full charge and riding 2km, figured I'd pushed hard on the 2km of hills...... Noticed it again tonight after a full charge and putting the battery into my bike.
12 cycles and 90% health. I've contacted the bike shop and Shimano Australia...