A battery unit comprises a plurality of accumulators distributed in rows, a support arranged along a row of accumulators of the plurality of accumulators, conductive strips attached to the accumulators of the row and extending over the support, a guide, the support being suitable for sliding into the guide, a metal strip extending in the guide, deformable electrical connectors fixed to the metal strip and designed to come into contact with the conductive strips when the support is fully inserted in the guide, and metal portions distributed along the metal strip, in contact with the metal strip.