Yeah, the first time that happens is really surprising. We had stopped on our way to our daughter's house and gassed up. Restarted the truck and drove on over to the house. Stayed a few minutes, went to leave, and the truck wouldn't start, no crank, no nothing. Showed about 12.0 Volts IIRC. New battery, checked the alternator and good to go. It was about a 5-6 year old battery.
IMO 3 batteries in 10 years is way too many. I figure at least 5 years for a battery. The battery in my car is 6 years old, and the one in Peggy's truck is 4 years old.