> I've never understood why cars don't just cut power before the battery is too low to start. The design of most cars can't tolerate losing 12V DC power withou

> I've never understood why cars don't just cut power before the battery is too low to start. The design of most cars can't tolerate losing 12V DC power without problems. Clearing superfluous codes after a battery swap is SOP. Cars are build for two simultaneous customers: regulatory regimes and work-a-day 13.5K miles a year workers that start (and thus charge) their cars at least every 48-72 hours. Other use cases aren't really considered. Some are better than others though. I have a 21 year old Nissan with a factory alarm and key fobs that sits for a month or more and starts fine every time. Heating helps a lot.