Ford was involved it'll break
The supply of lithium-ion battery materials is already stretched isn't it? This seems like a bad plan.
Do allow me to laugh: "Battery technology is advancing rapidly" :)) On what planet? xD
Should have more weight loss than that. There is no need for the lead acid component at all, make it pure lithium. It should have the cold cranking amps needed (except for maybe super cold weather) and also have energy capacity to power accessories. With any luck, we can replace the lead acid battery in older cars with lithium, plug and play with hardware in the battery to work with the traditional alternator.