Wait, what? I just jumped my car yesterday with cables. What is a lithium ion jumper battery? Is that something in newer cars?

Well, it isn't an integral part of the cars or anything. It is basically a chonky powerbank that can jumpstart a car.

It's exactly like having a separate car battery and jumper cables. Except with a relatively small lithium-ion battery bank rather than a traditional car battery.

Random example, no affiliation: https://no.co/products/power/jumpstarters

Sure, if it hasn't been sitting in your trunk for 6 months and all the charge leaked down.