One of the many changes in the new Model S Plaid is a new 12-volt Lithium-ion battery. The new battery replaces the conventional lead-acid battery, which has long been the industry standard in automobiles.
The goal for Tesla is to increase the life cycle and improve convenience for Tesla owners.
The new 12-volt Li-ion battery is lighter, smaller and has a longer lifespan than the older model battery. This move to Li-ion was coming for some time. Considering many Tesla owners see their traditional 12V lead-acid batteries die an early death, the new li-ion battery was a needed change.
The old Tesla battery had a rating of 33-amp hours and 12 volts. The low voltage battery has a rating of 6.9 amps and 15.5 volts.
The new battery makes the S Plaid faster and lighter, and that is never a bad thing.