Bigger battery is more capacity sure. But their point was that even without a big battery they have enough capacity to get close to maximum effectiveness, contrary to ajross saying that a hybrid's capacity is "not really" effective and "at best" helps "some".
braking system = circa 1G of deceleration possible (depending on tyres, coeff of friction, temperature, ... etc etc)
So max effectiveness is unreachable for any regen system on a consumer car hybrid or ev, by a factor of around 6x i believe?
With recognition of the mistaken framing (near max effectiveness) we're back to the larger ev pack has a greater ability to sink current, a larger ability to slow the vehicle than does a smaller battery (obvious considerations about inverter capability, wire gauge etc etc aside)
Their definition of effectiveness is the percentage of braking force that turns back into electricity and goes into the battery. If your regen system can only do .15G, but 90% of your braking is under .15G, then you'll have about 94% effectiveness by that definition. 94% is not max but it's near max.
It's not about what happens during peak braking, it's about what happens over entire drives.
And when they say "half or so of how fast I could stop" they're underestimating, that's a comparison to a normal but aggressive stop, not pushing the pedal into the ground.
It's NOT relevant to overall (tyre, brake system & engine braking & regen braking) braking system performance since that's a dynamic value variable over many factors constantly.
Every other EVs and HVs assign first half of brake pedal for regen and bottom half for mechanical brakes. Tesla uses bottom half of gas pedal for the same, which eliminates the need to accurately determine the appropriate pedal force that corresponds to intended braking force to be added up with regen to match intended deceleration. Mapping regen to gas is `set_motor_torque(1.25 * gas_pedal - 25);` and that's much simpler.
This seems a bit exaggerated. Staying regenerative-only does require sticking to about half or so of how fast I could stop, but so far that seems to work fine unless a light turns right in front of me or traffic acts up. Usually it says it gets high 90's or 100%, and it didn't go below 50% even when a stoplight did turn at exactly the wrong time. (2022 Ford Escape non-plug-in hybrid, recently bought used.)