When you are talking about battery packs with the capacity of "all electric"
cars, I'm not sure (but have a definite opinion) about how true that is.
When you have a 200 amp pack, and you can safely charge at up to 10 C, that
would be a 2,000 amp charge capacity! That is a hell of a lot of juice. I
can't imagine anything but an emergency braking exceeding that!

To handle braking loads, perhaps we can dump the braking energy into
a super capacitor bank and then use that to invertor charge the
battery at a normal rate...