Orion xs 50 amp dc to dc charger draining starter battery

[RyanBlaney12 (Randy)]

I have a 2020 ford transit 350. I have 600 amp hours of lithium batteries that I used a 40 amp Renogy dc to dc charger to charge them while driving. I had it set up to my ignition to start charging when I started the van. When the unit quit working, I bought the orion xs 50 amp dc to dc charger. I liked the idea of it sensing the alternator to turn it on. I have 6 AWG wire running to it because it’s a very short run of less than 3 ft. I hooked it up to the smart alternator settings, and everything seemed fine for the first day or so. I would get up in the morning and when I would try to start the van, it would barely crank, but would start. I looked online and seen if anyone else had this problem. From what I read, my settings might be wrong. Even though when I shut the van off, the app shows the charger off. So I did some other settings I found online, but it would still drain my starter battery. So I thought, maybe my battery is going bad. I went to O’Reilly and had it checked. Battery and alternator are good. So, I decided to just hook up the 12 volt ignition wire to turn it on and off. I pulled the jumper wire out, put the 12 volt ignition wire in the H slot, and turned off the engine shutdown detection. I turned the van on, it started charging, turned the van off, it quit charging. I got a load from sc to Mississippi, so I took off and everything was working fine. I stopped for the night, and the next morning, my van barely turned over to start. So, I decided to unhook the orion that day, drove the van around town, slept, the next morning, the van cranked right up!! Just like it used to when I had the renogy dc to dc charger installed. So, my question is, what do I have wrong?? I’m using the same grounding point, all connections are tight. I’m getting power to the unit from a 60 amp customer connection point that the transit has by my seat, that has constant power.. It’s the same one I used for the renogy. I have that going into the unit as power in, power out to the batteries, and I have it grounded to the van chassis, the same connection I used with the renogy. I have read that maybe my ground isn’t good enough?? This is throwing me for a loop! Thank you for any information. Much appreciated! Randy