A battery venting system that is useful for cordless power tools. The system can include a cell that may have a sleeve with a plurality of apertures surrounding a peripheral side face of the cell to enhance heat dissipation from the cell. A plurality of cells may be electrically connected to form a cell pack. A carrier includes an upper carrier and a lower carrier to sandwich a plurality of cells that are aligned parallel to each other. The carriers include at least one vent hole that are aligned with a gap formed from adjacent cells to define an elongated fluid flow path. A charger may be provided to receive a housing containing the carrier and may be provided with a fan to direct a flow into the fluid flow path.