Electricity storage system and method for controlling discharging of said electricity storage system

This invention allows balanced discharging in an electricity storage system that has a plurality of rechargeable batteries connected in parallel. Said electricity storage system has a plurality of rechargeable batteries (100a through 100f) connected in parallel and a battery electricity storage device (120) that, for each of said rechargeable batteries (100a through 100f), sets, at least an output voltage when said rechargeable battery (100a through 100f) is discharging. The battery electricity storage device (120) has a discharge control circuit (121) that allocates at least one of the rechargeable batteries to a master on the basis of at least the states of charge of or voltages across the rechargeable batteries, enabling the output voltages between the master and the other rechargeable batteries to varied. 本发明实现了具有并联连接的多个蓄电池的蓄电系统中的平衡放电。种蓄电系统包括：多个蓄电池(100a-100f)，其并联连接；蓄电池装置(120)，其至少设置为所述多个蓄电池(100a-100f)中的每个设置放电时的输出电压值。所述蓄电池装置(120)包括放电控制电路(121)，所述放电控制电路(121)被构造成基于至少电池残留容量或电池电压将所述多个蓄电池的至少个蓄电池指派用于主蓄电池，并且设置输出电压值