Kids Web Japan

Eco-friendly electric vehicles are just a step away from widespread use

The world’s automobile manufacturers are currently engaged in fierce competition to develop electric vehicles (EVs), which are powered by electric motors instead of gasoline engines. More energy-efficient than their gasoline-powered counterparts and CO2 emission-free, the vehicles are under development in countries around the world to help combat global warming. A number of issues remain to be resolved, however, before EVs appear on the road in large numbers. The distance they can travel on a single charge is relatively short, for example, and facilities for recharging them along the way have yet to be established.

Against this backdrop, a Japanese civic organization named the Japan Electric Vehicle Club drove an EV it had constructed from Tokyo to Osaka, a distance of 555.6 km, without a single stop for recharging. This drive, made on November 17, 2009, set a new world record, edging out the previous record of 501 km set by Tesla Motors of the United States less than a month earlier, on October 27, 2009.

A closer look at the record-breaking EV

The record-setting vehicle was a specially altered gasoline-powered vehicle marketed by a Japanese automaker. The Japan Electric Vehicle Club chose a model with a lightweight body, removed its gasoline engine and installed an electric motor along with the requisite control devices and batteries. Club members realized that to establish a new record they would have to make adjustments that would enable them to mount the batteries without wasting space. They selected high-performance Japanese-made lithium-ion batteries and, after repeated calculations and experiments, determined that 8,320 batteries should be just the right number to accomplish the 555.6 km journey.

Then, carefully calculating the dimensions of the space under the car’s flooring, they fabricated a battery casing that fit the vehicle body perfectly. And succeeded in mounting the batteries compactly with no wasted space.

Record-setting vehicle

Mira EV (constructed by the Japan Electric Vehicle Club)
Basic vehicle: Mira Van (Daihatsu Motor Co., Ltd.)
Powerplant: Brushless DC synchronized motor
Rated output: 14 kW
Max. output: 35 kW
Batteries: Lithium-ion (Sanyo Electric Co., Ltd.)
Total electric voltage: 240.5 V
Total electric power: 74 kWh
Tires: Eco Walker (Toyo Tire & Rubber Co., Ltd.)　
Passenger capacity: 2

Lithium-ion batteries

The lithium-ion batteries that powered the vehicle were cylindrical in shape, measuring 18 mm in diameter and 65 mm in length. They were the same kind of batteries that are used to power personal computers. It would take approximately 10 hours to recharge all the batteries the EV used in the drive.

Ongoing development efforts are targeting 1,000 km on a single charge

This unique EV traveled from Tokyo to Osaka at speeds of 40 to 60 kilometers per hour on ordinary roads and at an average speed of 80 kilometers on expressways. EV batteries consume the most power during acceleration at startup, and repeated stops and starts in traffic jams were particularly problematic. Since the rolling resistance of the tires increases on wet roads, energy efficiency also decreases in the rain. The Japan Electric Vehicle Club’s EV encountered rainy weather at some points during its journey and got caught in two large traffic jams. The fact that the new world record was established under these challenging, realistic driving conditions makes it particularly meaningful for further EV development.

The Japan Electric Vehicle Club reports that it plans to continue its efforts to extend the record further. Having set their sights on traveling 1,000 km without a battery recharge, Club members are proceeding aggressively with their preparations.

The EV can travel as fast as a gasoline-powered vehicle, and it provides a good level of driving comfort.

(Updated in March 2010)