My 14 has a lithium ion battery sourced from WPS I believe. Carl's Cycles in Boise put it in when I had the snowbike built. I never had an issue with it even in extreme cold. I carry a battery jump pack but never used it. With no kickstarter, I figured it was better to have it than not. I have converted my 14 (14.5 Dingy Factory Edition actually) to a 520 for this season. I don't anticipate any starting problems with the big bore motor. I believe compression remains the same or nearly so.