This discussion about 12V batteries failing is a head-scratcher for me. I have lived decades in some of the coldest parts of this continent, keeping a fleet of about a dozen vehicles. I never have had a lead-acid battery let me down. Sure, I have had them unable to crank out the needed amps at negative-hell-and-gone - that is absolutely par for the course. But -12ºC is NOT "cold", by lead-acid, and particularly NEW lead-acid, battery standards.
Now, if I lived in Miami - or spent my summers in Arizona :tongue: - I know that heat is a killer for Pb-acid cells. But the relatively frequent tales of dead 12Vs crippling Model Ss is a real mystery. What could be different about these from the batteries that have been maintaining ICEs for so many decades?
As an aside, as reliable as (I think) Pb-acid batteries are in the cold, as far as I am concerned, the real Achilles heel for Tesla at present is the utter inappropriateness of Li-ion technology in frigid climates. I am absolutely hoping we (Tesla) achieves an electrochemical breakthrough before they begin marketing a pickup truck - elsewise, no Alaska market for them. They'll have to confine themselves to Texas (horrors).