2003 Polaris sportsman 500 HO not charging battery

[Wilkechr]

So on this ATV the batteries keep dying to the point it won't start I'm on my 2nd battery this week it took me until this one to figure out that my ATV isn't charging it's on 12.75 volts when sitting in the ATV and it doesn't go up when being revved what are the chances it could be the rectifier/regulator vs the stator or CDI. I just replaced CDI and stator from a used ATV through a shop and I would hate for one of those to be bad. I was reading a couple of posts about the CDI but was hoping it was the regulator is there a chance?

[Mech]

I doubt the cdi is causing the problem. 

If the voltage doesn't rise when the engine is running then you need to diagnose the charging problem. You should download a service/workshop manual and follow the test procedure as written in the manual.. It could be as simple as a blown fuse or a broken wire.

[Jemelems]

Dumb question, but have you verified the charger is working? Maybe put an amp clamp meter on the power lead for s&g to make sure its sending voltage out

[Cj Winds]

Most likely its the regulator located behind the front grill or under the front rack.