Battery capacity grading mechanism

A battery capacity grading mechanism comprises a bottom plate, a battery containing device, a needle plate assembly and a top plate assembly which are sequentially arranged from bottom to top, and a supporting platform is arranged on the bottom plate; the battery accommodating device comprises a tray bottom plate assembly and a battery tray, the tray bottom plate assembly is arranged on the supporting platform and comprises a tray bottom plate, a linear bearing and a cooling fan, a tray placement area is arranged on the tray bottom plate, mounting holes are formed in the periphery of the tray placement area, and cooling holes are formed in the tray placement area; a linear bearing is embedded in the mounting hole; a heat dissipation fan is embedded in the heat dissipation hole; the battery tray is movably arranged between the tray bottom plate and the needle plate assembly; the top plate assembly comprises a top plate, a guide shaft which is arranged on the top plate and is in sliding connection with the line