Abstract: Described herein are battery packs and electric vehicles using these packs. In some examples, a battery pack comprises two portions/covers and a set of battery modules positioned within the enclosed cavity formed by these portions. A battery pack may comprise a set of pressure-relief valves positioned in and protruding through a wall of at least one portion. Each valve can be coaxial with a corresponding gap provided between two adjacent modules. The valve is configured to provide a fluid path (to the exterior of the battery pack) when the pressure inside the pack exceeds a set threshold. In some examples, the battery pack comprises an inlet tube fluidically coupled to the inlet port of each module and an outlet tube fluidically coupled to the outlet port of each module. A set of specially configured orifices or controllable valves is positioned on the fluid path through each module.