Alternative Fuels Data Center: How Do Hybrid Electric Cars A hybrid electric vehicle cannot be plugged in to charge the battery. Instead, the battery is charged through regenerative braking and by the internal combustion engine. The extra power provided by the electric motor can potentially allow for a smaller engine. The battery can also power auxiliary loads and reduce engine idling when stopped. How Hybrids Work - FuelEconomy The electric motor provides power to assist the engine in accelerating, passing, or hill climbing. This allows a smaller, more-efficient engine to be used. In some hybrids, the electric motor alone propels the vehicle at low speeds, where gasoline engines are least efficient. Automatic Start/Stop. How Hybrid Cars Work | Honda Engine Room As the hybrid car becomes more common, interest is undoubtedly growing. One of the most common questions on the minds of today's drivers is how a hybrid car works. From the workings of the hybrid engine to the process of charging a hybrid car, we aim to clear any doubts you might have about the hybrid car.