Just purchased used ATV, worked fine for awhile. Then on a day of trail riding it just went dead. No cranking, no lights, not even the neutral light. I charged the battery and everything seem to be fine for awhile and then dead again. I am assuming what ever is charging the battery has failed. Being new to ATV, like last week. Don’t know the make up of what this part would be called so I can replace it. On a car it’s called an alternator, what is it called on an ATV?