My rambling thoughts What doesn't make sense to me concerning using Lithium batteries in cars is that in many cases there is no mention of using any form of Battery Management System (BMS) alongside them. Having spent years dealing with Lithium batteries for RC modelling its always been stressed the specific requirements of Lithium, not overcharging, not overdischarging, charging at specific rates, maintaining voltage balance across individual cells, using only dedicated charges, storing ar specific voltages etc. Lithium battery chemistry is obviously far different from lead acid, individual cell voltages, internal resistance, the characteristics of charging/discharging seemingly to be completely different. My Lotus Exige came with a factory fitted LiFeP04 battery but the battery is "protected" by a separate dedicated BMS. Whilst you can buy a Lithium battery without a BMS, hook it up to your car and it works, charging it using your standard alternator/voltage regulator system (that has invariably been designed for lead acid use), you certainly can't be treating the battery in an optimum way IMHO And yes, (not as though I'm suggesting it can happen with car batteries unless really provoked) I have experienced a few Lithium Battery fires during my RC time, so am probably over cautious.