“So, if an EV uses 10kw to go a certain speed, then brakes, it will use 10kw to stop, again either through fiction etc or braking. Any charging effect can only be less than the 10kw output, considering those same losses due to waste friction, electrical resistance, inefficiencies of the charging/battery system etc.”
kw is power, not energy.
The charging during braking will be less than that during acceleration but it is still charging.
The ICE is burning fuel during braking. The EV is generating new fuel during braking.
Where does this new fuel come from?
The net output cannot be more than the initial charge, minus losses to waste heat, friction and resistance.
Any recovery is even less than the input to do the work that is now being collected via brake charging etc again, none of these syatens approach hi efficiency. And, the electrical power the battery is providing already is from other sources, about 90% on ave from petroleum or coal.
Exchange, not improvement.
Gorism.