I measured the pack voltage once after mowing the last time. If I remember right, it was down to 35.somethingV. I go back to recharge when the tractor almost can't move with any speed while the deck is ON. I can tell while mowing that the deck seems to quiet down (may be an indication of the voltage dropping and motors slowing down.) Like I said before, just rebuilt this deck and it runs SMOOOOOTH. The Fuel Gauge indicates almost absolute empty with everything on at the end of my mowing cycle, before going in to recharge. Of course, when I shut the deck off and stop moving, it comes up above the red. When the charger is running after a mow, the gauge indicates real close to the white line, and when "fully charged," the gauge indicates well into the white CHG section while the charger is on and just below the white/green line when the charger is off and batts have stabilized. While mowing, the Power Use meter indicates just up into the yellow a little bit, so i'm not overdrawing.
I think I will remove the charge controller and try the stock setup for a while, taking measurements on the pack as I go along. I may need a real good equalization charge, but I am worried that I have lost capacity over the winter. Water levels never dropped below the plates that I can remember since I purchased the batteries.
I might have to ask Harry for some of my money back and return some of these controllers. I'm not impressed with the operation and components. It kind of works, but if I can really only use it for a top-up charge over the winter, I'm in the garage enough to turn the timer on for a few hours. Honestly, just using the stock charger, I was probably overcharging up to 39.5-40V or so. I tried to keep the timer setting down to a minimum, but at least I was able to mow the whole yard on one charge and then some.