Manufacturing method of battery

A manufacturing method of a battery, the manufacturing method comprising performing roller conveying, by a conveying roller, of a bipolar electrode laminate that is an elongated sheet and that is heated, wherein

• the bipolar electrode laminate includes a first electrode active material layer, a current collector layer, and a second electrode active material layer, in this order,
• the first electrode active material layer is made up of a plurality of island portions extending in a conveying direction, with at least one gap portion extending in the conveying direction among the island portions,
• the conveying roller includes a heating portion at a position overlapping the gap portion or an opposite side face from the gap portion, and also includes a non-heating portion at a position overlapping a portion other than the gap portion or the opposite side face from the gap portion, such that when the bipolar electrode laminate passes over the conveying roller,
• a temperature decrease of the gap portion of the bipolar electrode laminate is less than 30° C., and also
• a temperature decrease of the portion other than the gap portion of the bipolar electrode laminate is no less than 30° C.