Please see version 2 (which uses a threaded rod between the base and handle for increased strength/durability) - https://www.printables.com/model/573501-dual-xbox-controller-carrying-handle-threaded-rod
This allows you to carry two controllers and spare batteries wherever you need.
Print with PETG for strength, supports are required under the bottom sides of the handle and in the middle of the handle.
The author remixed this model.