>Energy from gasoline puts you in motion. Frictional energy on the brake rotor/drum is expended to return the vehicle to a state of rest.
Most hybrids recover braking energy to recharge the battery.
Since efficiency is never 100%, you can never quite get there, but the lower bound is zero.
The vehicle won't even budge with zero input. It's nonsense to even discuss that point. The efficiency is way below 100%. A lead-acid battery is only 75-85% efficient. The rest is lost to heat. Lithium ION is 86% efficient.
A study extolling the virtue of the Prius says it delivers 32% of the power from the battery as power to the wheels. The gasoline engine only delivers 16%...the rest is lost in the form of heat out the exhaust and radiator (70%). The balance is due to braking friction, aerodynamic drag and frictional losses in the engine and drive train.
If the Prius is delivering 32% to the wheels, that means the other 68% is wasted is some fashion. It's clearly not a "reversible" process as defined in classical thermodynamics.