Hybrid vehicle drivetrains transmit power to the driving wheels for hybrid vehicles. A hybrid vehicle has multiple forms of motive power, and can come in many configurations. For example, a hybrid may receive its energy by burning gasoline, but switch between an electric motor and a combustion engine.
A typical powertrain includes all of the components used to transform stored potential energy. Powertrains may either use chemical, solar, nuclear or kinetic energy for propulsion. The oldest example is the steam locomotive. Modern examples include electric bicycles and hybrid electric vehicles, which generally combine a battery (or supercapacitor) supplemented by an internal combustion engine (ICE) that can either recharge the batteries or power the vehicle. Other hybrid powertrains can use flywheels to store energy.
Among different types of hybrid vehicles, only the electric/ICE type is commercially available as of 2017. One variety operated in parallel to provide power from both motors simultaneously. Another operated in series with one source exclusively providing the power and the second providing electricity. Either source may provide the primary motive force, with the other augmenting the primary.
Other combinations offer efficiency gains from superior energy management and regeneration that are offset by cost, complexity and battery limitations. Combustion-electric (CE) hybrids have battery packs with far larger capacity than a combustion-only vehicle. A combustion-electric hybrid has batteries that are light that offer higher energy density and are far more costly. ICEs require only a battery large enough to operate the electrical system and ignite the engine.[1]