TOYKO -- SIM-Drive Corp., Japan’s electric vehicle startup, has unveiled a new electric vehicle dubbed “SIM –LEI,” a four-seat sedan scheduled for mass production in 2013. “LEI” stands for “Leading Efficiency In-Wheel motor,” the company said.
Joining forces with SIM-Drive to develop its first commercial model using in-wheel motor technology are 34 industry suppliers. They include: auto manufacturers like Isuzu Motors and Mitsubishi Motors; component vendors such as Iriso Electronics Co. and Japan Aviation Electronics Industry; and material specialists Kureha Corp., Nikkan Industries Co. and Tanaka Kikinzoku Group.
The development goal was to build an EV capable of long-range driving. One critical performance objective was to achieve 300 km of range per charge. SIM-Drive said 300-km range approaches the range of gasoline-powered cars. The SIM-LEI prototype achieved a range of 333 km (207 miles) per charge in “JC-08 mode,” which represents general urban traffic conditions in Japan. When running at 100-km per hour, the prototype managed 305-km range per charge.
SIM-LEI demonstrated 333-km range per charge
The body, weighing 1650 kg, measures 4700 mm x 1600 mm x 1550 mm, is “as long as a medium-size sedan, and as wide as a compact car,” according to SIM-Drive. It seats four people. Its fastest speed is 150 Km/h. It takes 4.8 seconds to accelerate from zero to 100 km/h, the company noted.
Boosting range without increasing battery capacity
SIM-Drive said three factors contributed to the longer range per charge for the SIM-LEI. First, the SIM-LEI uses “in-wheel motor” technology along with a “component built-in frame,” both of which improve energy efficiency.
Second, the new model uses an all-steel monocoque body, which reduces body weight by supporting the structural load using the auto’s exterior in place of an internal frame. The SIM-LEI also uses what the company described as “super-low-rolling, friction-resistance tires.” Further, its super-low air drag body makes the SIM-LEI more aerodynamic.
Lastly, SIM-Drive used high power density batteries, which improved the efficiency of its energy regeneration process. As a result, SIM-LEI achieved AC energy consumption of 77 Wh/km, which is believed to be equivalent to 70-km per liter in terms of gasoline consumption. The battery capacity was 24.9 KWh, similar to that of competitors’ batteries. Thanks to better AC energy consumption, SIM-Drive claimed it was able to stretch the SIM-LEI’s range per charge.
The ability to drive longer ranges while achieving favorable AC energy consumption rates made the new EV model more energy-efficient compared to internal combustion engines, the company claimed. If recharging is restricted to night-time surplus electricity, SIM-Drive stressed that this type of EVs won’t require the construction of additional power generation plants.
The battery used in the SIM-LEI can be recharged as many as 6,000 times. If the EV battery is used as an energy storage device, its night-time charge also could be tapped during day-time hours to run domestic electric appliances, the company noted, indicating its potential to help reduce peak-hour power demand.
U.S. experts also have claimed growing fleets of electric vehicles could be used to store growing amounts of electricity as smart grids are built out.
--Yoichiro Hata is editor in chief at EE Times Japan