A battery system includes a can with a lip around an opening. At least an interior surface of the can is anodized and the lip of the can includes a longer and shorter side. The can further includes a flange on the longer side of the lip and a plurality of layers that are inserted into the can. The plurality of layers includes a battery cell and a thermally conducting layer with a fin and the fin has a spring force that pushes the fin towards the anodized interior surface. The battery system further includes a lid that is configured to cover the opening of the can, where the flange is configured to wrap around the lid when the lid covers the opening of the can.