I just replaced one in my four wheeler that was 07 also. It was ABUSED! I let it sit for months on end with out starting it or charging it, it lasted until this spring. So, I think if you keep them charged it helps a bunch, until it starts draging you are probably ok. When in doubt take it and have it tested, wont cost anything but time. Put it on a battery tender when/if it sits for prolonged periods, or take it inside if its going to sit a long time in the cold. I have quick connects on everything I own so I can use my tenders on it all, if I remember is a different story.
Coop