My wife's Biz 100 is still running the original battery that came in it back in '05. 10 years and counting. It's a sealed battery of some sort, don't rightly know what it is since it's up under the fairing and it's never given problems so haven't dug around to see what it is. If it works - why bother it? Just changed out the Yuasa in my XL200, it's only two or three years old, replaced it with a Sigma (I THINK that's the brand) sealed battery. We'll see how it goes.