Optimization of the Li-ion battery layout for EV

The next generation vehicles are developed all over the world to solve global environment problem. Expectations for electric vehicles are big. Hybrid-vehicle, Pure-EV, and Fuel-cell-vehicle are developed. Most vehicles use Li-ion battery. Li-ion battery will become the key-technology. KEIO University developed Eliica (electric li-ion battery-car) in 2004. Eliica proved the performance and utility of Li-ion battery by Max speed, Max Acceleration and driving range. Eliica uses unique structure called CBF (Component Built-in Frame). Batteries is mounted in an sealed aluminum frame called BBF (Battery Built-in Frame). The heat from batteries at charge and discharge is hard to be ambient because BBF is sealed-up. The life of batteries depends on the temperature upon use but Present Eliica tends to become too high. To hold down the upper limit temperature to about 25. Improvement plan was devised by experience upon the charge and discharge test paid attention to endoergic reaction of battery and charge time. Li-ion battery has a characteristic that reacts endothermically in charging. But this reagency is effective less than 10A. The vehicle stops during charge time. If BBF is opened, there are less problems than running. The problem was settled by opening the edge of BBF and battery layout. This formality is effective for other cars and the other field.