I had a similar issue with a beautiful little Super Isolette on a trip to Chile a few years ago. The shutter decided to quit working at the beginning of the trip and I used up 10 rolls of film for naught. Funny thing though, there was no battery to blame. I think these types of problems can happen on cameras with or without batteries.
I gave myself half the blame, it was not a battery issue, but with an AE, AF, camera, you can listen and look for problems, but if it is underexposing 3 stops you may well miss it. I really did not think I had to test new out of the box Nikons, would have done it regardless, but I was a bit pressed for time.
Of course the body with slides over exposed, and the one with negative film underexposed. I tried to compensate with processing, but it was a waste of money with the negatives, the slides only were a bit off, one stop, so pulling was possible.
New cameras should be tested.
Batteries, after a few hard lessons, I made sure there were spares in the case. Have had some modern batteries die, but I have to say newer batteries are much better than early ones.
You can easily become blase, and my luggage has a half dozen chargers and sets of cords. Often I buy a charger / spare battery combination, as a back up for both.
When I did some paid work, I used to verify the sync before I loaded film, or even shoot a test roll at the local one hour, trying to see if I could screw up the settings. My Nikons and Metz CT 60s with the right module really would not let me screw up. I gave the photos to the lab techs, who then did not charge me, and felt I was prudently covered.
I did have a Kodak branded processor scratch a dozen rolls of film because they did not keep the machine clean-- there are always things to go wrong.
Regards, John