摘要 |
A maximum dischageable current Idmax obtained when electric power output from a battery is increased from a battery current Ib and a battery voltage Vb at present under internal resistance R at present (an operating point 510) until the battery voltage reaches a lower limit voltage Ve (an operating point 520), is shown as follows: Idmax = Ib + (Vb - Ve) / R. Therefore, in accordance with multiplication of the lower limit voltage Ve and the maximum dischageable current Idmax, it is possible to predict maximum dischargeable electric power at which the battery voltage does not become lower than the lower limit voltage even if discharge limitation is temporarily relaxed, as a relative value with respect to the battery voltage and the battery current at present. When the discharge electric power limitation for the battery (the power storage device) is temporarily relaxed in accordance with a discharge request made by a load, a discharge electric power permissible value is set to correspond to the maximum dischargeable electric power, such that the output voltage of the power storage device does not fall outside a controlled voltage range from the lower limit voltage to an upper limit voltage. |