E70 Increased Battery Discharge while Stationary

[JCL]

Very interesting posts.

While it could be incompetence, I think I would classify it as an organizational incompetence rather than a individual engineer incompetence. Think of how Ford would have specified an alternator: they used one with xx amps on the last model, so they used the same on the new model. Every now and then they will move to a smaller and lighter battery for weight saving, but I suspect that they simply don't use overcomplicated charging profiles and such. They also know how their customers use their vehicles.

BMW must have a room full of charging system engineers. They invent variable charging profiles, customized to different battery types. They turn off the alternator when they can, for acceleration figures (witness efficient dynamics). They assume nobody would drive primarily 5 km trips, because they don't in Germany. They have sleep programs that sometimes don't run because there are miniscule current draws keeping the vehicle awake. And the result is that it is all horrendously complicated and interconnected.

Penguin suggested that BMW has trouble admitting mistakes. I agree. I think the specific mistake they are having trouble with is admitting that more engineering doesn't fix a problem that has at its root, too much engineering.