Supercaps can provide higher peak energy flow, either for acceleration or regen. They can buffer the battery from rapid energy flux.

I doubt very much they are going to actually store even 1kWh of total energy, because mass storage isn’t their strong suit.

At least a 10x factor below.

A table you may be interested in:

https://en.wikipedia.org/wiki/Energy_density#Table_of_energy...

>> Fascinating. I’m always intrigued in these style of answers.

Me too. Does anybody know a technology site/community, focusing on the theoretical limits of what various technologies could do, and how do they work , instead of the day to day news?

The stackoverflow family I’d sited is good for discussions like this and is often nicer than the halo site when it comes to inclusion of questions (I use SO everyday but trying to give back by answering a questions or even asking one I have had not so great experiences). I really like the astronomy and physics exchanges.