Apparatus, methods and systems are provided for cooling high power batteries. A plurality of carrier assemblies is stacked to form a cell stack. Each carrier assembly has a thermally conductive backing plate and a frame integrally formed therewith. A lithium-ion pouch cell (having a pair of cell tabs) is adhered to a front surface of the backing plate. Each cell tab is paired with a tab of opposite polarity of an adjacent battery cell. Thermally conductive compression bars are placed over the paired tabs to maintain electrical contact between the tabs. The compression bars also transfer heat to a cooling plate on top of the cell stack. Each carrier assembly incorporates a heat spreader sheet on a surface of the battery cell, a compressible foam sheet in front of the heat spreader sheet, and a thermally isolating sheet in front of the foam sheet.