I have read in numerous threads some problems associated with the 12V lead acid batteries in various battery electric vehicles. Tesla had a batch that was of poor quality that got to be replaced, I read on another forum a similar problem with a Kia Soul EV. It seems to me that the 12V lead acid battery is with a lower standard of reliability than the lithium batteries in EVs. There is of course a reason to keep the 12V batteries: they are the electrical standard for all electronic accessories in cars. Their low voltage is relatively safe for human interaction (nobody dies of an 12V electric shock...) Their cost is relatively low (depending on the 12V battery size and characteristics we are talking about $75 to $150 as their price). However, they weigh a lot, and they have a relatively small (2-5 years depending on where they are installed) lifespan. So replacing them with an alternative would be interesting. I know that Zero Motorcycles don't have any other batteries than the main 11.4kWh lithium battery (I own a 2014 Zero S with such a design). When we turn the key, it's the main battery that furnish the energy to do the power on self test and health checks before the main contactors are energized. A small wire feeds energy from the main pack to the booting computer to power it for the tests. This avenue has not been used so far on electric cars, as far as I know (correct me if I am wrong). Another possibility would be to use a lithium iron battery to provide the 12V source for accessories and boot process of EVs. They cycle well and are safer against fire hazards. What do you think about either of those ideas?