Battery swapping has become one of the most important ways to supply energy to electric vehicles (EVs)

since it takes a very short time to replace fully recharged EV battery (EVB) packs and is convenient to manage. It leads to growing market penetration of the EVs to develop the battery swapping station (BSS). The optimal capacity configuration of electric vehicle battery swapping station

which is able to recharge the depleted EVB packs locally

is studied. Firstly

the system structure of the swapping station system as well as the operation strategy of “charge and swap” is described and two evaluation indices of service availability are proposed. Secondly

the timing simulation model for swapping station operation states is analyzed. According to the output of the model

service availability indices are calculated. A mathematical model is developed

with the equipment annual cost as the objective function and the scale and service availability as the constraints. The differential evolution (DE) algorithm is used to solve the mathematical model. Finally

the optimal configuration of a case in point is made. With two different days’ swapping demand randomly taken

the indices of swapping service availability are calculated and the state of the BSS in each period is analyzed. And the sensitivity of the result of configuration is briefly treated.