Well, I always had a problem with the old Yuasa battery on my hyper821 during winters in West Texas (-10)! And then called in the guys at Antigravity Batteries all they told me that I have warm up the battery on a cold day. So, I leave the headlights on for few mins before I hit the start button, and it starts every single time! Yes, if you switch on the bike and don't warm up the battery, sure you will have a sluggish start, but never in the last two years, I had problems with cold start while using Antigravity Battery! Just warm it up takes 2 mins! 3rd year in, still going strong!