Ironically, the way you set up the poll one could vote for the top three options and "none of these options" at the same time.
So - W, would you prefer to 'wire' that up.. in parallel, or in series.. or via a reverse polarity shunt-spike? L.O.L...
"Well, we knocked the bastard off!"
Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).
I'd guess two chemistries, one optimised for rapid charging from the regen, the other optimised for whatever you get from the turbo.The idea of using two battery types has been around since at least 1993, if not in F1.