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Electric buses have superior environmental performance because they emit no CO2 and other exhaust gases while driving. However, in terms of more popularization of electric buses, it is essential to improve battery performance and realize user-friendliness of charging. To resolve these issues, a concept “short range running and frequent charging” was formulated. Under this approach, the authors have studied methods of greatly reducing the amount of large, heavy, and expensive battery. Research on non-contact inductive power supply (IPS) system has also been conducted as a way of improving charging convenience. A longterm operation test of electric buses was performed in Nagano prefecture as part of a project organized by the Japan Ministry of the Environment from 2011 to 2014. For this project the short-range frequentcharging type electric buses, “Waseda Electric Buses (WEBs)” were developed and tested on public roads to make clear the environmental performance and energy costs. WEB-3, one of the test vehicles, was driven for 41,724 km without any major problems and had advantages to reduce 28 - 42 % of CO2 emissions and 57 – 64 % of energy costs, compared to conventional diesel buses. And it was estimated on Matlab simulation model that total energy consumption could be reduced by 11 % with vehicle weight reduction, modifications of drivetrain and other components.

The degradation mechanisms of lithium iron phosphate battery have been analyzed with 150 day calendar capacity loss tests and 3,000 cycle capacity loss tests to identify the operation method to maximize the battery life for electric vehicles. Both test results indicated that capacity loss increased under higher temperature and SOC conditions. And also, large increase of internal resistance on the high temperature and high SOC conditions was confirmed by AC impedance tests. The real cycle capacity loss characteristic was derived by subtracting the capacity decrease due to calendar capacity loss during the cycle test from the overall capacity loss characteristic obtained from the cycle test. As a result, it is found that the real capacity loss contains not only structural disorders of electrode but also degradation factors due to the chemical reactions. Characteristics of degradation were quantified with equations based on the chemical kinetics. With this degradation prediction, an operation method was proposed that is compatible with the long life of batteries and the safety driving of a vehicle. As a result, with optimizing the SOC range used in the operation as follows: 30-10% in the warm seasons, 45-25% in the cold seasons, it was found that batteries can last 4 times longer than it used with high SOC range in every season.