Have vive pro and the battery connector slowly died out on me so after eventually getting another battery (VRURC t2055) that was a bit bigger than the original with more capacity. I set out on a mission to somewhat recreate the vive battery waist holder thingy so this is basically that but for a bigger battery.

[ASSEMBLY]_(nuts not required, bolts recomended) use 2x 2.5m screws and nuts to hold plastic retainers in to hold the battery in. pause the print at layer 596 (easiest to do in slicer software) AFTER YOU HAVE CORRECTLY PAUSED IT... insert hex nuts in the holes at the side. i used a soldering iron at its lowest setting (210C) to snugly ensure the went in smooth and straight and tight. unpause printer and allow it to print over top. add the bolts later.

USE SUPPORTS 4 [MAIN PEICE] make sure to remove them from the nut pockets. ensure generous supporting inside back connector

[BACKPLATE] print on side (lines will go up/down. this ensures strength/flexibility) Be sure to sand down the back plate before inserting into the main holder (THEY ARE VERY SNUG) dont rip layers apart :) ..snug but not too snug, trust me

SUPERGLUE HIGHLY RECOMENDED but not required.

It works for me at least. Have fun.. Play On.. :)