Mostly driver convenience. I drive a mid-tier VW with infotainment, power seats, satellite navigation, etc. If I don't drive the car after a few days it takes a

Mostly driver convenience. I drive a mid-tier VW with infotainment, power seats, satellite navigation, etc. If I don't drive the car after a few days it takes a few minutes for the car to fully boot up. No radio, GPS, climate control goes full blast, and it won't know what my power seat settings are. Now imagine having to do that every time you pull the key out, run in the supermarket, and go back to the car. We're demanding a lot from the car battery lately and the BMS needs to know where it stands.