1 C current fully discharges battery in 1 hour. Thus 4KWh battery running 60 KW engine means 15C current, and it would discharge the battery in 4 minutes (in a

1 C current fully discharges battery in 1 hour. Thus 4KWh battery running 60 KW engine means 15C current, and it would discharge the battery in 4 minutes (in a very simplified linear model).