What is the difference in lithium phone batteries - that can reliably tell us they have exactly 17% charge left and how many amps they can output in real time - and lead acid car batteries that just say "hell, even *I* don't know if the car will start next time or not, so good luck out there fam"?
Car subs are full of posts that just say cars don't give a warning light because cars don't give a warning light. What's the actual scientific reason?