Exactly. From what I've read elsewhere it sounds like charging and usage profiles are tied into a complex hysteresis that starts with the car knowing when the battery is fresh. This plays a role in the energy management system shutting down various loads in order to preserve the battery for at least one engine start with some safety margin as the battery ages. But to what degree charging behavior is modified, and to the degree that it actually affects the life of a new battery being treated as an old one, well, it’s not clear to me it’s anything appreciable. It seems to me like a highly over engineered system.

And with the car being so smart about the battery state, you'd think they would include the battery as a Condition Based Service (CBS) item so the car would show the driver when the battery was due for replacement. The dealers would get more proactive battery sales, at least from the people that dutifully visit the dealer when the car tells them to. And assuming a nominal battery age of 4+ years, BMW would probably avoid having to replace most of the batteries under warranty. Of course the CBS items are also relatively easily reset by an end-user, and we wouldn't want that! Yet it's OK to reset the oil change, brake fluid, vehicle check, and other items via the instrument cluster’s service menu.

Also, I've heard that disconnecting the battery sometimes results in the car needing to be recoded due to various modules losing their coding, not just a window one-touch or steering wheel easy exit feature needing to be reactivated by the flick of a switch or two while standing on one’s head. Shouldn’t all of the module coding be in nonvolatile memory? Will simply disconnecting and reconnecting the battery result in any modules needing recoding by the dealer in order to function properly?

I’m about ready to replace my battery, so any clarity on this would be appreciated.