To provide a battery improved in service life and safety of the battery, and formed by combining a mechanical and thermal packaging system with a flexible element.

This battery includes a plurality of electrical energy generating elements 1 formed with an electrochemical cell that is packaged in a flexible sealed envelope, and a system for the mechanical and thermal conditioning of the elements. The battery is characterized in that the conditioning system forms a structural body 9 made from thermally conductive substance; the structural body has two longitudinal members 10, 11 and a plurality of cross-members 12 connecting the longitudinal members to form between the cross-member housings 13 having the respective generating elements 1 in the inside; the structural body includes a circulation path for a thermal conditioning fluid; the circulation path has two channels such as an upstream channel 14 and a downstream channel 15 that are formed in the longitudinal members 10, 11, respectively; and passages 16 formed in the respective cross-members 12; and the passages are in fluid communication with the upstream channel 14 and the downstream channel 15.