A battery system and a method of assembling the battery system are provided. The battery system includes a thermally conductive base member, a thermal transfer member, a thermally conductive adhesive portion, and a battery module. The thermal transfer member has a metal plate with a top portion and a bottom portion. The bottom portion is disposed on the thermally conductive base member. The top portion has a substantially arcuate-shaped groove extending inwardly into the metal plate. The thermally conductive adhesive portion is disposed in the substantially arcuate-shaped groove. The battery module having a first pouch-type battery cell with a first outer housing with a first end portion. The first end portion is disposed on the thermally conductive adhesive portion and is disposed above the arcuate-shaped groove.