I've been reading alot of post about a dead battery after putting the bike up for winter. I pull my battery and put it in side where its warm so it dont sit in the cold, a battery tender dont do the trick when the battery sits in long cold weather. I have a battery tender and dont use it that much, guess it would do well on newer bikes with all the electric crap.

 

Warm or cold a battery sitting will loose some of its charge. True in colder weather is worse. If a battery is not being used a battery tender is a good idea no matter what the weather is like or at least drive the bike a couple times a month to keep the battery charged. I ride mine all year round but we do not get much snow here but I did ride it once this past winter in the snow as it was the only way I had to go.