Mazda to lease approx. 100 units of Demio EV (Mazda2) in Japan from October; coil-switching system in motor

Demio EV. Click to enlarge.

Mazda Motor Corporation will begin leasing the Demio EV in October 2012. The Demio EV is an independently developed electric vehicle based on the Mazda Demio (known outside of Japan as Mazda2). Mazda intends to lease approximately 100 units in total, mainly to local governments and corporate customers in the Chugoku region of Western Japan (where Mazda’s headquarters are located).
The Demio EV features a 20 kWh, 346 V Li-ion battery pack and Mazda coil-switching electric motor with maximum output of 75 kW from 5,200 to 12,000 rpm and maximum torque of 150 N·m (111 lb-ft) from 0–2800 rpm. Driving range is up to 200 kilometers (124 miles) on the JC08 mode test cycle, as measured by Mazda.
Motor. The Demio EV uses a permanent magnet three-phase alternating current synchronous electric motor employing a coil-switching system. Conventional electric motors provide either high torque in low revolutions, or low torque at high revolutions. The coil switching system enables the motor to have both of these characteristics in one motor by switching the number of coils according to the rotational speeds, Mazda says. Making the most of the motor’s characteristics, the Demio EV realizes strong acceleration response at take-off and smooth acceleration response at high speeds.

The Demio EV motor. Click to enlarge.		Acceleration tuning with the coil-switching motor. Click to enlarge.

The motor in the electric drive unit in the Demio EV is smaller than that of an ordinary motor capable of generating the same power output, thanks to the employment of the coil-switching type motor. Additionally, the battery pack case is made from aluminum to further reduce weight. As a result, the weight gain of Demio EV associated with a change to EV is limited to only 190 kg (419 lb) more than the base model, resulting in the total vehicle weight of 1,180 kg (2,601 lb).

Positioning of the battery pack and power electronics. Click to enlarge.

Battery. The Demio EV’s Lithium-ion battery achieves high energy density through the use of 18650-type battery cells connected both in parallel and in series for optimal configuration. Due to the high energy density of the battery module and small size of the cooling system, the Demio EV is equipped with a compact battery pack. As a result, the Demio EV is able to offer the same cabin space and cargo volume as the base model.
With ordinary use, the battery is expected to maintain 80% of capacity even after 5 years.

Battery pack. Click to enlarge.

Optimal positioning of the battery pack close to the center of the vehicle improved longitudinal weight distribution and weight ratio of sprung and unsprung in comparison to the base model. The result is a balance of agile handling and high-quality, comfortable ride.
A regular charge at 200VAC, 15A takes about 8 hours. A fast charge (CHAdeMO compliant) with a 50 kW charger takes approximately 40 minutes (80% charge).

Drive modes in the Demio EV. Click to enlarge.

Drive modes. In addition to D range for normal driving, the Demio EV has an E range for eco-friendly driving which focuses on power control while increasing the amount of electricity regenerated under braking. Furthermore, a Charge Switch button makes regenerative braking work even stronger when the vehicle is driving down-hill.
Other features. A 100V power feed system can be mounted in the tire pan space beneath the rear trunk (factory-installed option). It can supply up to 1,500W and 100V of AC power to home appliances. It can also be used as a power source at outside and also as an emergency power source in the event of natural disasters.
A Vehicle Proximity Notification System is designed to alert pedestrians of the vehicle’s approach. When driving at speeds of 25km/h (15.5 mph) or less, speakers mounted inside the engine bay generate pseudo-driving noise. The noise generated changes in accordance with speed and whether the vehicle is travelling forward or in reverse.
The Demio EV is installed with an air conditioning system dedicated to EVs. A Positive Temperature Coefficient (PTC) heater directly heats air going into the cabin within seconds and the cooling system uses electric compressor.
The price (including tax) is ¥3,577,000 (US$44,746). Through the lease program, Mazda intends to gain further knowledge of electric drive technology and the usefulness of such products to the customer.


Source: Green Car Congress