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“Onboard-charge” electric bus drives 1,100 km

Jiang Jiming can hardly believe what he experiences: two pre-charged electric buses each traveling 1,100 kilometers from Beijing to Yangzhou, a city in Jiangsu Province, without a hitch.

But, of course, they still burn some fuel on the way, indirectly. When the battery runs low, an engine kicks in automatically, charging the battery.

With an intention to cooperate with the developer of the bus, Yangzhou municipality, a major bus-manufacturing base, has a team headed by Jiang driving the two buses from Beijing to Yangzhou to test their fuel consumption and performance.

Their developer is the Beijing BIT Clean EV Co., Ltd. The electric bus is driven purely by electricity. And a common lead-acid battery rather than lithium battery is used. Prior to going on the road, the battery was charged from an outside power source. When the battery runs low, an onboard small engine starts automatically and drives a special generator to charge the battery, thereby providing undisrupted power for the vehicle. This may be called an “onboard-charge” electric vehicle. 

In hybrid vehicle development, domestic businesses at present focus their attention on “weak” and “medium hybrid” approaches. These schemes are limited in energy saving, which is at maximum about 30 percent. The third choice, the “strong hybrid” technology, is more complicated, which is what BIT Clean EV’s electric bus based on. Currently pure EVs powered by lithium batteries are too expensive. The “onboard-charge” electric vehicle powered by conventional lead-acid battery might be a new choice for new energy vehicle development. 

Yang Yusheng, a member of the Chinese Academy of Engineering, says the bus developed by BIT Clean EV can also be called a “dual-charge” electric vehicle, with a technical route in between a plug-in and a purely EV. “Dual-charge” refers to pre-charging and onboard charging.

“Despite the use of fuel, the vehicle is driven purely by electricity,” Yang says. “And the vehicle’s fuel saving can reach a remarkable 50 percent or more. In addition, lead-acid battery is inexpensive. Structurally, the vehicle is not complicated and this makes mass production easily possible.”

Fu Yuwu, secretary-general of the Society of Automotive Engineers of China, agrees to Yang’s views and believes that the technology should be first applied in the public transportation sector, where the problem of battery charging can be more easily resolved and fuel efficiency and emissions are major concerns.

Test drive shows that the 11.3-meter electric bus consumes 18.4 liters of fuel per 100 kilometers, compared to the 40 liters for an ordinary bus of the same length. A full charge of the bus at night, when the price of electricity is relatively low, costs ¥25 ($3.68) and allows the bus to travel 80 kilometers. If the bus runs 200 kilometers per day, the cost of energy – electricity and fuel – comes to about ¥160, compared with some ¥500 for an ordinary bus.

The electric bus is more fuel-efficient than the hybrid bus, too. According to statistics released by the Guangzhou No. 1 Bus Co., the Foton hybrid bus it operates consumes 32-33 liters of fuel per 100 kilometers.

One of the buses that were driven from Beijing to Yangzhou is installed with a 64-cell lead-acid battery pack and super capacitors. The cost is just round ¥150,000. The cost of a lithium battery pack for a purely electric bus of similar size is ¥600,000-¥800,000. The BIT Clean EV vouches for an operational life of five years for the lead-acid battery pack.

It is a complicated and proprietary technology to make batteries that discharges and recharges simultaneously, according to Yang Yusheng of the Chinese Academy of Engineering. “This is the core technology for the ‘dual-charge’ electric bus,” he says.

BIT Clean EV plans to manufacture power assemblies consisting of the engine, the generator and related parts and controllers for the electric bus, according to company chairman Du Ju. “With this approach, we intend to cut cost, improve production uniformity and speed up the technology’s commercialization,” he says. He estimates that, if the more than 20,000 buses serving Beijing are all replaced by “onboard-charge” electric buses, daily savings in fuel cost can reach ¥5-¥6 million and emissions of greenhouse gases will come down by a big margin, too.

Rewritten by Raymond Chen based on author’s article carried by

21 Shiji Jingji Baodao or 21st Century Business Herald



Beijing BIT Clean EV Co., Ltd. has an annual production capacity of 500 electric coaches, 1,000 electric medium buses, 5,000 other electric vehicles, 10,000 electric motorcycles as well as key parts and components.

BIT Clean EV has five shareholders: BIT Century Technology Group, Zhongshan Fast Power Source Co., Ltd., Beijing Institute of Automobile, BIT Zhongxing Technology Co., Ltd. and Guangzhou Sea-Sky Changxin Technology Co., Ltd.

Beijing Institute of Technology (BIT) is a key shareholder of the company and its EV Center of Engineering and Technology provides major R&D of electric vehicles and key components. The Center is headed by Dr. Sun Fengchun who is a Cheung Kong Scholar of the Ministry of Education and vice president of BIT.

(For details about the company, please visit

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