I've had this battery box for a while now and use it for travel. Now I uploaded it here on Printables. It is durable and you can throw it in your bag among other things.
Comes in two designs, one for AA batteries (7pcs) and one for AAA batteries (7pcs as well).
If you print the upper part in green and the lower in red, it kind of indicates if the battery is charged ( insert +pole up) or discharged (insert +pole down).
Also check out:
https://www.youtube.com/channel/UChKp-968z1i5PN29gbR7YfA
https://www.cgtrader.com/rorys3d
The author marked this model as their own original creation.