Ok, this is really weird. I built a box for portable power, for a starlink internet system. I'm working on clearing land and don't need internet there 24/7/365, only when I'm there. So got a plastic truck box, put in a new lithium ion 12vdc battery, Victron mppt 75v/10A charger, Victron Smart Energy Sense and Phoenix 12/375 inverter. Battery is fully charged, holding between 13.2 - 13.9vdc.
I first plugged the starlink in and it kept booting up, then losing wifi, then restarting etc.
Today got to messing with it and thought.. hmm. plugged the starlink into regular mains power and it works fine, boots up, stays up.
Ok, so this inverter has an eco-mode where it looks to see if there is a load, and if so, then comes on.. but I don't have it in eco mode. Maybe it is doing that anyway. Tried both ways, eco and regular, same thing.
Then I unplugged the starlink and plugged in a small flat panel tv, like small computer monitor size. Powered that up and it came on and never went off. Inverter just idling about 20-30 watts.
Added two loads. no problem, but.. as soon as I plug the Starlink into the inverter, alone or with another load.. the inverter goes off for a bit, starts up, goes off, starts up. It's the darnedest thing.
I'll try to get some video if needed to prove what I'm seeing.