Using lithium-ion batteries, the Toyota Prius Plug-in Hybrid provides clean, fuel-efficient electric-powered running in urban areas for longer distances and at higher speeds than the conventional, third generation full hybrid Toyota Prius. Over longer distances, or when the limit of battery power is reached, the system automatically shifts to conventional petrol power.

The concept model is a development of the new, third generation Prius, and builds on the core technology of Hybrid Synergy Drive specifically to meet the needs of urban motorists. It is a full hybrid vehicle in which both the electric motor and petrol engine can drive the wheels. A fully electric EV mode is used for shorter distances, while the petrol engine provides a true long-range capability.

Toyota also attained a compact and practical packaging design for the battery pack. Toyota Prius Plug-in can be also be quickly recharged, from a conventional household electricity point, or a public charging post.The Toyota Prius Plug-in Hybrid Concept is similar in format to the Hybrid Synergy Drive used in the new Prius, but with the nickel-metal hydride battery pack replaced by a new, high-output lithium-ion battery.

The battery is more compact and has a higher volumetric energy density, so it does not compromise vehicle weight and packaging. Perhaps more importantly, it can be recharged much more quickly than the nickel-metal hydride type: the battery in the Toyota Prius Plug-in Hybrid can be fully recharged in 1.5 hours from a 230v power supply.

The battery allows strong, seamless acceleration up to a maximum 100km/h in EV mode. On a full charge, it can cover approximately 20km in EV mode, six miles further than the nickel-metal hydride battery in the latest Prius model. Over longer distances, the car operates as a regular full hybrid.

The extended EV capability brings CO2 emissions down to around 60g/km. Even greater CO2 savings can also be gained if the electricity used to charge the battery is drawn from renewable sources, such as windmills and solar panels. Simply put, lower the percentage of energy derived from fossil fuels, better the car's well-to-wheel performance.

The Toyota Prius Plug-in Hybrid Concept is comfortable, convenient and practical as the latest generation Toyota Prius. In its sister model, the air conditioning can be activated remotely, when the vehicle is plugged, enabling the cabin to be brought to the right temperature before setting off.

To help drivers maximise the benefits of driving in EV mode, it is equipped with a Hybrid System Indicator, which includes information on the EV driving range, based on the level of battery charge. An engine starting point display has also been added to emphasise the increase in EV driving range.