Renault Zoe Battery cap

5mm version shown in picture. 8mm version is just proud of the top lip

I have repurposed a Renault Zoe battery I put this together to block off the holes. Its a relatively loose fit and I hold them in place with a bead of silicon. If you make them 5mm tall they slide around under the top lip.

I printed fast at:

0.28mm layer height

2 perimeters

3 solid layers top/bottom

20% infill

For such a simple model you could use whatever you think would work best for your printer.