Nissan charges into hybrids with ePower technology

System is solely driven by electricity

Nissan has developed a hybrid powertrain that uses the gasoline engine solely to charge the vehicle’s battery pack, with the wheels only driven by the electric motor.

The OEM’s ePower system borrows from the firm’s EV technology used in the Nissan Leaf, but adds a small gasoline engine to charge the high-output battery when necessary, eliminating the need for an external charger.

Nissan said: “[EVs] generally require a bigger motor and battery because the motor is the only direct source to drive wheels. This has made it hard for the automotive industry to mount the system in compact cars. However, Nissan has cracked the code and learned how to minimise and reduce weight, develop more responsive motor control methods and optimise energy management. As a result, ePower uses a smaller battery than the LEAF, but delivers the same driving experience as a full EV.”

In conventional hybrid systems a low-output electric motor is mated to a gasoline engine to drive the wheels when the battery is low or when traveling at high speeds. In Nissan’s system, the gasoline engine is not connected to the wheels and only charges the battery, but unlike a full EV, the power source originates from the engine and not just the battery.

Packaging has also been problematic for OEMs, as EVs require large battery packs to achieve the range targets that consumers demand, but in this system the battery is 1/20th the size of the Leaf’s, and is housed under the front seats.

Other firms have developed similar technologies in the past. General Motors introduced its Chevrolet Volt to the market in 2011. The vehicle combined a gasoline engine and electric motor and battery pack. Although the Volt could be plugged in to be recharged, the onboard combustion engine could also act as a generator.

But housing multiple powertrain systems is complex, and many have seen it as unnecessary as efficiency gains aren’t strong enough. But this is something that Nissan disputes.

“Because ePower relies on the engine much less frequently, its fuel efficiency is comparable to that of leading conventional hybrids, especially during around-the-town commutes,” said Nissan.

tags: Nissan Hybrids & EVs