I don't use a battery tender either. I some times go for a month or two without riding here in Kansas. Mine always starts up in the spring just fine. I do usually get a day or so in January or Febuary where I can get out and ride though. These new AGM batteries do not loose their charge like the old lead acid ones do. But when they fail it is all at once. They will work fine until they are dead. No amount of charging will bring them back to life. But they usually last me 5 to 7 years.