[serialk11r]

This is neat, it's good to see it working in practice. I think a car pulls like 1-2W when it's switched off, which is far higher than the leakage current of a capacitor. However, to be able to leave the lights on at a stop for a while after the car hasn't been used for a week or two for example without having the voltage dip too low, I would throw a battery in albeit a lighter one.

Originally I was thinking of replacing my battery with a 36Ah Shorai (at 300 bucks it's basically 3 times the cost of an AGM lead acid battery, and supposedly they can tolerate much more cycling so it might eventually pay for itself), but seeing this makes me think a small (lithium?) battery plus capacitors for starting might be the better solution.