Charging problem

we had a 96 and we replaced the battery every year if we didnt unhook it in the offseason but thats the only problem that we had. Im pretty sure that it is charged by the stator. I know that on ours when you pull up the kill switch you can hear the efi cycle. I wonder if he shuts it off but leaves the key or the kill switch in the run position if the efi keeps cycleing. Maybe try to make sure both are in off position other than that not really sure.