| 摘要 |
PURPOSE:To realize charging without lowering energy efficiency and in compliance with the utilization condition of a battery by selecting one mode wherein desired discharging electricity quantity can be obtained from plural charging modes different in preset charging electricity quantity. CONSTITUTION:Three charging modes of economy, normal, and long drive are set to e.g. the secondary battery of an electric automobile. Usually a normal mode is selected which is having an energy efficiency of about 80% and discharging electric quantity having the maximum capacity ratio exceeding 90% also the excellent balance between both the sides. At the time of a short travel distance by one time charge, an economy mode is selected wherein an energy efficiency is about 90% and 60% of battery capacity can be charged. At the time of a long travel distance by one time charge, a long drive mode is selected to perform overcharge exceeding 140% due to the necessity for accumulating the maximum electricity quantity in a battery though energy efficiency becomes about 60%. |
