2007 Sportsman 500 EFI charging issue

Guys,

Things going along fine through the winter after I located a loose battery connection. Was very nice to have it go when needed. Battery was 1 year old.

Then … started one day … twice … and then got the dreaded "click"

Put it on a battery tender overnight and it started the next day … once.

Pulled the battery and had it tested. Replaced it. Battery was from Advance Auto. Just under 1 year old. Originally cost $104 … and had a 3 month warranty … good grief!

Now have same issue. The charging circuit must be screwed up. Can someone give me an overview of how this works on the ATV? What voltage should I expect while the machine is idling that would indicate it is charging?

Recommendations?

Thank you!!!