I haven’t really had any time to work on this, but here is what I threw together:
The design integrates the LED module into a board via an “x thing” style plate that doubles as a washer for truck mounting screws. The design is intended to be used with m5 socket cap screws since I seriously hate stripping hardware. The LED module is attached via 2 small m2.6 screws threaded directly into the 3d printed plastic (I would likely use super glue to attach these). If waterproofing was needed, silicone or perhaps hot glue could be used to encase the LED module, making removal difficult but hopefully unnecessary. Wires for the LED module would likely be routed downwards through a small hole drilled in the deck, but a slight modification to the design would allow the cables to come out on top of the deck as well.
TL;DR - This is an “x thing” with an integrated battery indicator.
note: only compatible with the EL1/EL2 version of the battery indicator
STL File:
Hoyt St. EL1-EL2 LED battery indicator anti sink plate r1.STL (945.8 KB)