At least some some Tesla Model S' have had a problem with vampire current draw. I.e. processes in the vehicle consuming a significant amount of power when the vehicle is parked, with power, ostensively, "off". Draw was up to 4.5 kWh (7.5% of a 60 kWh battery, 13 miles, 21 kilometre) per day. A series of system software updates had apparently failed to cure the problem for some users.
For David Noland of Green Car Reports, the problem was finally traced to the lead-acid 12 Volt battery, which was failing to hold a charge & so was constantly being charged from the traction battery.
http://www.greencarreports.com/news/1088929_life-with-tesla-model-s-electric-draw-vampire-slain-at-last / LiIon Tesla Model S Elon kiloWatt kilowatt kilo Watt LiIon lithium ion battery lead acid 12 Volt battery charge recharge battery self discharge metre meter kilometer range Exide over charge overcharge warranty service replace defect defective replace fail /
