Our OEM Interstate U-2200's lasted one month short of 10 years. I NEVER ran a desulfation charge on them in all that time. The only charger was the one built into the inverter, it's a three stage and must be a pretty good one to let them last that long. I could have set the inverter to do it, but there was no automatic desulfation setup so I know it was never done.
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft, HWH Active Air
Charter Good Sam Lifetime Member, FMCA,
RV'ing since 1957, NRA Benefactor Life, towing '21 Jeep JLU Rubicon Ecodiesel