BeswinVR P2- Head Back Pads with Power Bank Holder for BOBOVR M2, Oculus Quest 2 strap, Halo Strap- Black

This is probably the best solution for mounting a battery pack to a Bobovr M2 head strap but for a few pieces of velcro a bit of padding and some plastic it's a bit pricey, but well thought out and of good quality and very comfortable

I attached it to my BoboVR headstrap and the counterweight and comfort are immense. So yeah, if you are a Bobo user, I can personally recommend this with all of my non-credibility. Do it!