Assembled battery

An assembled battery, comprising:

• a plurality of unit cells each comprising a flat wound electrode body, and a battery case including a pair of opposing side surfaces and accommodating the flat wound electrode body, the unit cells being arrayed in an array direction that intersects the side surfaces;
• spacers disposed so as to sandwich the unit cells in the array direction, each spacer comprising a flat portion disposed so as to oppose the side surfaces, and a rib portion protruding from the flat portion towards the side surfaces;
• and
• a restraining member that restrains the arrayed unit cells and spacers, in such a manner that an inherent stress is present in a direction in which the unit cells and the spacers are compressed along the array direction,
• the flat wound electrode body being provided with an elongate positive electrode, an elongate negative electrode, and a fixing member,
• the positive electrode and the negative electrode being stacked so as to be insulated from each other and being wound so as to yield an oval shape in a sectional view about a winding axis that is a transverse direction perpendicular to a longitudinal direction,
• a winding end of the flat wound electrode body being fixed by the fixing member,
• the flat wound electrode body including a flat portion including the stacked positive electrode and negative electrode extending along a major axis of the oval shape and being accommodated in the battery case in such a manner that the flat portion opposes the side surfaces,
• the flat portion comprising a pressing region including a pressing site opposing the rib portion, and a moderation region other than the pressing region,
• the pressing region including a center of the flat portion in a winding axis direction, and including a first pressing region spanning a direction along the major axis, and
• the fixing member being disposed in the moderation region.