Tesla (TSLA) replaces 12V lead-acid battery with 12V lithium-ion battery to save space and weight in car: https://pandaily.com/china-made-tes...-model-equipped-with-12v-lithium-ion-battery/ " China-made Tesla Model Y Performance Model Equipped with 12V Lithium-Ion Battery Pandaily Posted on November 30, 2021 ... The 12V lithium-ion battery is much smaller than conventional lead-acid batteries used in petrol cars, which allows Tesla to save space in the front of the car. Also, this kind of battery also has a longer life cycle. ... "
It makes sense to replace lead-acid with lithium-ion battery since there are tons of lithium-ion batteries in production.
This 12v batt keeps critical systems running if the high voltage pack has an issue. Musk is a fan of maxing out vertical integration … especially after some numb nut US company secretly outsourced their lead acid batt contract to China … who further subbed it to Vietnam. Quality choked quickly and this Li-ion was the fix. Sensible move by TSLA and likely that contractor will have their execs inflating their golden parachute after firing their remaining three shop floor employees.