JanGeo you are the regulator
I have a similar setup myself. I just prefer to recommend an automated 3 or 4 stage charger to people who don't understand proper charging or don’t have the time to watch it themselves.
And ya the Deltran chargers are a lot for what they are, but for someone like my brother who wants to connect it and walk away and then forget it for a week, Deltran is the way to go. I really like the Iota chargers in the larger amperages as well and they are more reasonably priced. Again you can build them yourself for a lot less if you know what you’re doing
WOW, 20KW that is some serious power. Do you have a link to them?