Thanks for Bernie sharing that great model - please like his model as well.
Printed in PLA 0.2mm layer height without supports and 15% infill (10 or 5% should work as well).
First put the two parts of the battery holder together then place it on the Gridfinity (credits to Zack Freedman) base plate.
You can glue the parts together but it is not necessary.
The author remixed this model.
Modified to be attached to a 3x4 Gridfinity plate with connectors - see files.