My equipment always stays under a lean to, never directly exposed to elements. Never used a battery tender, but do use block heater. My old tractor lasted 14 years with battery replaced once. The kioti is 2010 vintage and replaced battery this year. The only winter issue i have is freezing lock. Thats cause the inside cab in 75 and its 10 outside. While operating theres never an issue. It freezes lock overnight. I found that by not latching doir there is never an issue the next day.