Batteries are a crap shoot anymore weather you let them just sit or have a maintainer on them.
The one in my 2000 Kodiak 400 was still going strong when I sold in in 2017, 17 years of cold, sitting, snow plowing and whatever else. It never did fail to start the machine.
But as I type this I wonder if there is a circuit going to something electronic on these new machines that might draw some amps even when the Kodiak is turned off. I might have to do some testing.