I ran an optimate on my 750ss but winter months just made starting a problem. When not ridden for a week or so, even with optimate, the battery was just not up to turning all that mass running in lovely molasses (well, 15w isn't molasses, but you get the idea). Once things warmed up, the bike fired up right away with the same battery. Oh yeah, the nice cold soak also effect battery output. Optimate saves your battery, but doesn't insure winter startup!