BFL, I spoke with the same fella you did probably. He also told me he would ask as of yet I have not heard back from him.
To explain this is exactly what I did. I drained the ut1300 to almost empty. I hooked the converter directly to the battery with foot long 8 gauge cables. I set the voltage at 14.6 and left it on the constant voltage not 3 stage. The converter fired up and did indeed charge at about 50 amps for a short time and then cut out. I am talking after about 1 minute. I was also monitoring the voltage at the battery which was slightly lower than at the converter. So then I turned up the voltage so I was getting 14.6 at the battery. I cut out quicker. Then I turned down the voltage enough to where it would run at about 40 amps and that worked. So then after a good bit of experimenting around I decided I would mess that with second pot. I found that indeed did adjust the current up and down. Of course with the higher current it would then cut out quicker. So in the end I installed in my wfco and adjusted it where I will get just about 30 to 35 amps when the battery is drained about 20 percent. It starts to slowly drop as it tops off. I have the voltage set at 14.6. I am perfectly happy with this. Lion suggest a 45 amp charge rate but also points out it can take up to a 100 amp charge rate. The bms on LION shuts off current at 14.7 on the dot. I found this in my experimenting with the converter.
When I did have the alternator in the system I watched the battery getting charge at 90 amps while running the motor, I drove for about 15 minutes and that battery was amazing just guzzling the amps. I bought this battery for the convenience and the cool factor a lot more than a need factor. If I ever need a quick charge I will just put the fuse back in and let the alternator charge it up. With just one battery (my son in law has the other one) I am not to concerned with using the alternator once in a great while.
I have bought other powermax converters in the past and have been pleased. I will have the other new converter in my rig for a back up.
So to sum it up I could get higher current just not the full 55 and I would have to use higher voltage which as the battery topped off it would cause the bms to shut it down and I don't want that to happen.
Now you know the rest of the story. :)
