Well, I have been trying to get support from Zendure this whole time, OMG they are the fucking worst. I don't think it's just a translation problem, they seem to actively be trying to stop you from getting support. I submitted a ticket as above and their response was not even factual, they claimed that I needed an MC4 to XT90 cable, but the SBP only has XT60s, and I was asking about the AC port not the DC port. The next day they apologized for saying XT90 but continued to insist I was talking about the DC port on the SBP, 650W max. The next day they said "Oh sorry, we totally misunderstood you, we are checking the answer and will get right back to you" and then ghosted me.
Four days later I wrote them again, "Hey, any update?" and got a completely DIFFERENT person saying "We don't have an AC to DC cable!" ARGGGG! After telling them they were wrong again another 3 days passed before they responded "Oh, that cable, the one included with your station. You should look around for it, and don't go making any cables to replace the one you don't have"
Ok, so my options are I don't have the cable, they won't sell me the cable and I can't make my own cable. Is that really supporting the customer? So if any of you still have your cable please put a meter on it and let me know which plug goes to which pin, the polarity of DC is usually pretty important.