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Nissan introduces series-hybrid powertrain with Note e-POWER in Japan; small pack, small engine, LEAF motor, low price

In Japan, Nissan Motor introduced its new series-hybrid drive system called e-POWER along with its application in the Note. This marks the first availability of e-POWER technology for consumers, marking a milestone in the electrification strategy under Nissan Intelligent Mobility.

e-POWER borrows from the EV technology in the Nissan LEAF. Unlike the all-battery-electric powertrain of the LEAF, e-POWER adds a small gasoline engine to charge the high-output battery when necessary, eliminating the need for an external charger while offering the same high-output. Nissan says that although e-POWER uses a much smaller battery than the LEAF (1.5 kWh vs 30 kWh), it delivers the same driving experience as a full EV.

Chief powertrain engineer Naoki Nakada says minimizing battery size and compartmentalizing powertrain components to fit a compact vehicle were the first challenges.

Compared to LEAF, the batteries are 1/20th the size and made to fit under the front seats without having to sacrifice interior space.

—Naoki Nakada

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Differences between powertrains. Click to enlarge.

The e-POWER system features full electric-motor drive—the wheels are completely driven by the electric motor—the EM57 traction motor from the LEAF—which delivers a maximum 254 N·m from 0-3008 rpm. The power from a high-output battery is delivered to the e-POWER’s compact powertrain comprising a gasoline engine, power generator, inverter, and a motor.

The engine is the 1.2-liter, three-cylinder HR12DE. In general a three-cylinder engine tends to be louder and with more vibration than a four-cylinder engine. Nissan used an outer balancer to reduce vibration and noise, achieving quietness equivalent to that of a four-cylinder engine.

In conventional hybrid systems, a low-output electric motor is mated to a gasoline engine range extender to drive the wheels when the battery is low (or when traveling at high speeds). However, in the e-POWER system, the gasoline engine is not connected to the wheels; it simply charges the battery. Unlike a full EV, the power source originates from the engine and not just the battery.

e-POWER delivers massive torque almost instantly, which enhances drive response and results in smooth acceleration. Also, the system operates very quietly, much like a full EV. Because e-POWER relies on the engine much less frequently, its fuel efficiency is comparable to that of leading conventional hybrids, especially during around-the-town commutes.

Nissan is offering the Note e-POWER to its Japanese customers in three trim levels: S, X and Medalist. Fuel economy on the JC-08 cycle is 37.2 km/L (87 mpg US, 2.69 L/100km); 34.0 km/L (80 mpg US, 2.94 L/100km); and 34.0 km/L, respectively. Pricing for the entry-level S-trim starts at ¥1,772,280 (US$16,900).

Development History. Nissan is actively pursuing a zero-emission, zero-fatality world for driving through its EV program and autonomous drive technology. To make this vision a reality, Nissan is developing “Nissan Intelligent Mobility,” which anchors critical company decisions around how cars are powered, how cars are driven, and how cars integrate into society, all while staying focused on creating more enjoyable driving experiences.

In 2006, Nissan’s engineers were able to reduce the battery capacity to match its competitors’ hybrid vehicles while still delivering desirable EV qualities, such as quietness and efficient energy use. In addition, application of Nissan’s technologies, such as the integration of a power-generating engine, electric motor drive for compact car use, strengthening of the powertrain’s rigidity and improvements in NVH levels, became the foundation of e-POWER and its implementation in the compact-car segment.

Nissan is committed to developing electric-powered powertrains that use various fuels to cater to the different requirements of the world’s markets. e-POWER is but one example of that quest and will strengthen Nissan’s lineup of electric-powered powertrains. Nissan is also conducting research and development of the SOFC (Solid Oxide Fuel Cell) fuel-cell vehicle.

At the SAE 2016 Range Extenders for Electric Vehicles Symposium starting today in Knoxville, TN, Nissan will present a usability study of a fuel cell range extended EV (FC-REEV). Nissan has developed powertrain systems models to simulate usability issues—such as charging time—for BEVs and FC-REEVs.

Comments

Brian P

... or a device to game the Japanese emissions and fuel economy testing procedures, and probably Euro NEDC while they are at it.

Roger Pham

A serial hybrid suffers from losses from generator, at 95% efficiency, then inverter at 95% eff then motor 95% eff for total efficiency of 85%.
A parallel hybrid like the Prius has 3/4 of the torque directly mechanically transmitted from the engine with zero loss, and only 25% via motor-generator route at 85% efficiency.

The 1.2-liter engine with 10.7 compression ratio can best manage 34% thermal efficiency, while the Prius' engine can manage 40% thermal efficiency.

The Versa Note has lower aerodynamic efficiency than the Prius.
Overall, should have lower MPG than the latest Prius due to lower-efficiency items as above, such as losses in the motor-generator route, lower-efficiency engine, and lower aerodynamic efficiency.

The e-Note has a 109-hp motor plus a 80-hp generator, for a total of 189 hp of e-power. The Prius has only a 70-hp e-motor plus a 25-hp motor-generator, for a total of 95 hp of e-power.
The Note has a 1.5 kWh battery pack while the Prius has only a 0.75 kWh battery pack. Though the engine is only a 3-cylinder which may cost $500 less than the Prius' engine, and the lack of the planetary power-split unit may save another $500, though the doubling of battery capacity may cost around $500 more. while the doubling in e-power and in battery capacity will cost thousands more. At roughly ~$35 per hp of e-power, the 95 hp excess of the e-Note may raise the price by $3,325. Over, the e-Note may cost Nissan around $2,500 more than that of the Prius, on the price tags, due to excess amount of e-power and of battery capacity.

Profit margin to Nissan probably won't be as much as that of the Prius, if both cars are priced at the same amount.

Yet, the e-Note can put out only 109 hp max, vs 121 hp of the latest Prius.

Lad

At last Nissan has an answer to their CVT problems.
Rather radical solution...what?

SJC

Davemart,

Ford won several awards for their recent 3 cylinder engine.
They did not want to do balance shafts which rob power so the imbalanced flywheel changed the motion where they could design the mounts to compensate.

In this case the 3 cylinder was a compromise. Nissan has wanted to build a hybrid ever since they licensed hybrid Camry technology from Toyota. This is their first attempt at a hybrid outside that license, which expired.

Trees

It all comes down to cost, convenience, and drive character. This design may be less complicated as compared to Prius. Engineers can either make the engine run more efficient or another direction is to maximize battery usefulness. Nissan is the latter given they think the future is electric drive. The car would require a new set of thinking skills as compared to traditional hybrid. Also, I would guess the setup provides maximum latitude to improve and simplify. This design may be easier to standardize. Hybrids seem to have incredible demands to tailor power train to specific car needs. Manufacturing cost may have a better go with the Nissan approach. Given the motor is cheap as compared to transmission. Reducing battery need is a winner for both weight, cost, and reducing inconvenience. Control should be easier. Improving engine efficiency should be easier. Nice to have a built in heater source and generator. Acceleration performance should be better than Prius. They may have generator power directly to charger or have a way to improve efficiency by powering motor and utilizing excessive power to charge battery.

Herman

Roger, your point is well-taken on mechanical vs electrical conversion efficiency, but this really only matters if the car experiences a lot of steady state operation, which the typical Note doesn't. The high charge/discharge rate lithium chemistries showing up in hybrids today are capable of 40-50C sprints (see the Malibu and the Acura NSX) and for stop/go situations in urban Japan traffic this may be the best overall solution. An engine and generator matched and mapped for this application will do better than the peak thermal efficiency numbers imply, and such a thing hasn't really hit the street yet. I'm looking forward to the outcome.

SJC

Watch tuners put more batteries under the back seat to get a series EV, another 4 kWh could give it 20 miles around town.

Davemart

I was not criticising the Ford 3-pot, I don't know anything about it.

I was responding to someone saying that it was not very good by pointing out that even if that is the case, one poor implementation does not make 3 pots a bad idea, and the one in my car is fine.

laszlo

Please correct me if I am wrong. Nissan's series hybrid design is a good scalable platform for future PHEV and various extended range BEV's, saving productions costs in the long run.

Juan Carlos Zuleta Calderón

Unplugged vs. wireless charging? See my latest article published today on Seeking Alpha: http://seekingalpha.com/article/4019641-unplugged-vs-wireless-charging-nissans-e-power-got-probable-lithium-supply-crunch?v=1478272396&commenter=1&comments=show

gryf

The e-Note may be a great marketing move for Nissan. Roger Pham is correct that efficiency is less than 85% on the Series Hybrid, however this is not much worse than the Nissan Versa Note with a CVT (probably getting around 88% efficiency). The entry level price is US$16,900 which is less than $2k more than the price of a Nissan Versa Note with a CVT (around US$15,200) for a full hybrid. The standard Nissan Versa Note does not get very favorable reviews either, nowhere close to to the Honda Fit which it competes.
Using the Nissan Leaf Electric Motor gives the e-Note 110 HP and more importantly 254 N·m (187 lb-ft) torque from 0-3008 rpm which would be better than the competition.
Also, the e-Note fuel economy looks competitive to the Toyota Prius C which gets 82 mpg on the JC08 Test Cycle.
Possibly Nissan could use this setup as the basis for a Nissan Leaf PHEV (as @Laszlo points out). Sell it for less than $25K and you have real competition to the Chevy Volt or Prius Prime.

philmcneal

anyone know what a prius retails for in Japan? at 16k USD this could be the cheapest hybrid ever, go Nissan!

Bobcom52

My guess is Nissan saw an opening after dieselgate. Make a car with the fuel costs/ performance of a diesel without the pollution problems inherent. If they got it right it should be a big seller in that market sector.
Without a plug it is unfortunately just another fossil fuel vehicle.

gorr

IM interested to buy and i will carefully check my resulting mpg compared to my 36 mpg 2005 dodge neon.

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