Not me.
Is a battery tender like a chicken tender or a tenderoni?
My bikes stay in the shop. I keep the shop above freezing (around 45) when I'm not out there because the machines have liquid coolant so that can't freeze. My Lincoln gas driven welder is in there as is the gas drived diesel fired pressure washer. The farm tractors and equipment are in the other bay next door. I've never used a trickle charger and I never use gas stabilizer. I just start the bikes up every 2 weeks and warm them up. I make sure the gas tanks are full when I put them in for the cold weather. The only equipment that gets stabilizer is the zero turn, the push mower and the Troy-Bilt in the tractor bay. I'm a little leery of gas stabilizer. A few years ago there was a rash of gummed up carburetors on snowmobiles that had Stabil in them over the summer...remember, summer is winter for a sled. I don't want to think about gumming up those Kehin injector bodies or injectors.
A few years ago I bought one of those fancy computer controlled chargers with the pulse de-sulfation cycle on it. I've used it on the tractors a few times but neither bike has ever seen any charger trickle or otherwise and the battery in the T100 is OEM and it's an '03.
I know, now that I said that, the batteries will both puke this winter. If they do, they will both be replaced by Hawker's. If I could get Optima's in that size I'd prefer them but the Hawker is an AGM too.
Triumph alternators have a nice habit of putting out almost maximum amperage/wattage at just above an idle so warming up can be just an idle and plenty of juice is going to the battery.