> 12200 Wh/kg Most ICE engines have efficiencies from 20 to 35%. Taking an average of 25% effciency, batteries have to essentially aim at about 3000 Wh / kg M

> 12200 Wh/kg Most ICE engines have efficiencies from 20 to 35%. Taking an average of 25% effciency, batteries have to essentially aim at about 3000 Wh / kg Most battery motor systems have a round trip efficiencies of about 80%, so to compete with ICE engines, EV systems have a target of about 4000 Wh/kg. edit : I also forgot to add about regenerative braking. For on road EV vehicles, regenerative braking can capture about 70% of the energy lost in braking. So, while a battery can store just 450 Wh/kg, averaged total energy, expended from the battery terminals, averaged over time, would have to be higher. It also makes sense to calculate the average total energy stored in the vehicle, rather than the energy densities of the fuels. For a 300 mile range, assuming an average 30 mpg fuel efficiency, you would need about 10 gallons, about 38 kg. So total stored energy in the vehicle in form of fuel, is 12200 * 38 = ~ 465 kWh. But, of this energy, only 25 % is converted to usable movement, i.e, about 118 kWh. However on a Model 3 LR, which has a range of 300 miles per charge, the battery capacity is 80 kWh (Tesla claims 75 kWh). So there is no basis to compare energy densities of various fuels directly.