An exemplary traction battery securing assembly includes, among other things, a platform to support a battery pack, and a bracket supporting the platform in a position spaced from a vehicle structure. The bracket moves from a less elongated position to a more elongated position in response to a load to permit movement of the platform and the traction battery relative to the vehicle structure. An exemplary traction battery securing method includes, among other things, elongating a bracket in response to a load to permit a traction battery to move relative to a vehicle structure.