V-mount and D-tap power problems
To anyone who has similar questions, I think I solved it. Pay attention to voltage inputs to your devices. The blackmagic monitor I was using has a power input of 12v using the two-pin barrel connector. The barrel connecter d-tap cable I was using was unregulated therefore it was pushing out more than 12v. What I need is a l-series dummy battery connected to d-tap regulated down to 8v or so, which do exist. The only reason my entire system didn’t fry was because my battery was only about a quarter charged. If it was full, I would have sent almost 18v to the monitor, probably killing it and maybe some other stuff along the way. Check input voltages on everything you’re planning on connecting to your battery.