Definitely sounds like a faulty battery tray, so I don’t know that I would even bother trying to check or test it—the battery trays are designed to be semi-disposable, “sacrificial” components (originally designed to run off of alkaline cells), and are relatively cheap in the grand scheme of NV components:

USGI ANVIS Tray on eBay

Beyond that, if it’s a used battery pack, it may simply be that it’s faulty, as the ANVIS LPBPs are not necessarily the most durable components either, hence the availability of “Ground Optimized” battery packs like the AB Night Vision LPBP-GO:

https://tnvc.com/shop/ab-night-vision-lpbp-go/

Not only is the LPBP-GO significantly ruggedized and environmentally sealed in comparison to the USGI LPBP (and deletes the battery trays altogether), it is also “dual fuel,” and can be run off of either AA or CR123 cells, giving you a little bit more flexibility in terms of battery commonality with other accessories.

However, and not to open a can of worms, if you’re using a “clone” mount, it is certainly possible that the problem may be on the mount side, and perhaps some combination of the specific battery tray and the mount are not jiving well and delivering power properly.

Finally, if I were wanting to do some weird, one-off stuff with an ANVIS system, I probably would and have reached out to either our own resident Mod here @chosos, or I would reach out to Derek again (Relicraptor). Our build techs can work on ANVIS as well, but we don’t usually keep a huge stock of parts for those systems, and you might end up at the back of the queue for RMAs / we don’t normally like to do too many odd, custom, or “non-standard” stuff on customer systems as we’re not really set up for that, though we have on occasion with full disclosure about potentially non-warrantable work, and they’ve cobbled together some very interesting prototype or experimental stuff for me from time to time.

For programmatic and/or organizational work, we typically refer folks over to our friends over at Aviation Specialties Unlimited (ASU-NVG), who are every bit the aviation SMEs in the same way we specialize in ground systems.

~Augee