That sucks but it makes sense. I keep mine on a tender all winter. Temps in my garage stay between 36 and 40 generally.
My first one lasted 4.5 years, battery tender only over the winter. When it died - it went dead - right now - and I had to park it and go buy a battery 45 miles away at a dealer on a sunday .........
That was August 09. That replacement is still in the bike, 6+ years. Battery tender goes on every time the bike is parked in the garage. Even when in the camper the tender is on.
I know I got a good one, and I can tell the time is near. Just hoping to squeeze it out until they start salting the roads.