The ICE then promptly dumps 60-70% of the gasoline's potential energy into the environment in the form of heat and emissions, and EVs can also capture energy th

The ICE then promptly dumps 60-70% of the gasoline's potential energy into the environment in the form of heat and emissions, and EVs can also capture energy that would otherwise be dumped as heat from the ICE car's brake rotors. So in terms of useful work extracted from that energy, that battery holds the rough equivalent to 8-10 gallons of gasoline, of course at the cost of weight, space, degradation, refueling time, etc.