How long does the original battery last? In my case, almost 5 years from manufacture date of my bike. Over the last week or so, I noticed the bike was taking longer to start in the cold evenings after work than in previous winters. Today, I backed it out of my warm garage, fired it up, started to move forward and the bike died. I thought I'd let the clutch out too fast, because it started right back up. A few blocks later, I noticed my trip odometers had been reset to zero. I glanced at the clock and saw that it had reset, too. No further problems for the rest of the day, but I think I'll replace the battery so it doesn't strand me at an inopportune time.