To provide a battery grid that has a mechanical strength equal to a reciprocating type expanded grid while maintaining the speed of manufacture as a rotary type expanded grid, and its manufacturing method.

In the manufacturing method of this battery grid, a disk cutter which has arranged on the circumference, with an interval, a protruded cutting blades, that develops in mesh shape while forming a slit on a lead alloy sheet, is arranged in step from the side end of the lead alloy sheet along the moving direction of the lead alloy sheet. Thereby, an expanded grid that has no twist in the bridge portion is manufactured continuously. For one rotation of the rotating axle of the disc cutter, a mesh having the same number of slits as the protruded cutting blades can be made. And since the disc cutter is made to have a sufficient strength against the sheet strength, even if the thickness of the disk cutter is made thicker, interference with the adjoining disc cutters is prevented as the disc cutter is arranged in a step shape.