I don't have a way of storing my dead batteries other than a plastic bag which is an eyesore to look at and manage. Also we don't have any dead-battery pick up function where I live, but I'm able to store it and deliver my used up/dead batteries to our local recycling function, which is definitely the safest and only way to handle your dead batteries. 

!! Please don't throw batteries in your mixed trashcan.!!

My slicer settings:
0.32 layer height
0.6mm Nozzle
3 walls / perimeters
Printed with PLA
No support / raft / brim needed
100% Infill (You really don't save a lot of grams from using lower infill in this model, also making it 100% makes it tougher against the weight of dead batteries)

But other than it being 100% infill then any of the settings doesn't really matter, you can print it at 0.12 LH or 0.48 LH, it would still function the same way.

The model measures are: 100mm x 83mm x 180mm
My print time: 4H 30M