One thing with all of the boats in the game, stock or modded, is to use the knot gauge, not the standard telegraph. When you run at Ahead 1/3 on the gauge, the boat attempts to do 3 knots, which does drain the battery rather rapidly. Instead, use the knot gauge by clicking on the hamburger menu below the telegraph. Now click on the "1" one knot mark, and you should get quite a few more hours out of your batteries. I was reading of one of the S-Boats that left out of Bremerton Washington enroute to Dutch Harbor for their first war station in March of 1942, and they were only getting as little as 6 hours out of their batteries, and would have to sometimes lay still submerged for the cover of darkness, and then have to stand to more for the engines to charge the batteries, since they wouldn't hardly charge. They sent them to war in that... yeesh!... Of course, my dad went across the Pacific in early '43 in an LST, and then they later rode out a hurricaine in another... again - yeesh! "Nothing to it", he says...
Sorry, got distracted... Another thing - when you activated the FotRSU mod, and then removed Webster's S-Boat mod, did you empty the Save folder? That would still have some bad data in it, if you hadn't emptied it, whether you saved a game or not.
