I just wanted a battery box that looks like a battery, because - why not :-)
It holds 12 AA batteries and 18 AAA batteries. Rotating the cages releases the batteries one after another. Inside, there is a tunnel for discharged batteries waiting for you to charge them, so they do not mix with the charged ones.
The case prints with no supports. The infill was cca 20%, it does not matter. Set the resolution somewhere at 0.2 - 0.1, there are many round edges, so that it looks pretty smooth.
I used Fillamentum PLA Extrafill "Vertigo Grey" for the body and PLA Extrafill "Rapunzel Silver" for the top and bottom. It looks great and it makes the surface look smoother than it actually is. As for the lowest part, I switched the fillaments during the print to make the metal-like look of the bottom.
I uploaded stl for the individual parts, they should be easy to print.
Important: while slicing, check the integrity of the outer surface, there are thin walls at the cut-off parts of the rings.
If you are lucky, it is not necessary to glue the model together. You may wrap a tape around the inner tunnel, so the cages are perfectly aligned. You may also use some tape on the inner tunnel and the top to make the three pieces to hold better together, if it prints too loose. I recommend to join the tunnel parts and the top well, otherwise someone just grabs it at the top roughly and the bottom falls apart with all the batteries on the ground.
It may need some slight sand-paper adjustment of the lower parts of the cages, if it does not turn smoothly. I designed it with no spaces between the parts, so that it aligns perfectly with the other parts. It is always easier to spend some minutes with the sand-paper than to print again ;-)