A heat exchanger for a battery has fluid-carrying panels and defines a multi-sided enclosure for enclosing at least two sides of the battery. The heat exchanger has first and second fluid-carrying panels defining first and second flow channels, where the first and second fluid-carrying panels are arranged at an angle to another. The heat exchanger may also include a third fluid-carrying panel defining a third flow channel, and being arranged at an angle to the second fluid-carrying panel. The heat exchanger has first and second plates sealingly joined together along their peripheries and defining a fluid flow passageway between their central fluid flow areas. The second plate may be compliant, its central fluid flow area being deformable away from the central fluid flow area of the first plate in response to a pressure of a fluid inside the fluid flow passageway.
