farm and fleet uses an eclectic pencil engraver to mark purchase date on the battery

heard them marking one when I was near the register not to long ago

I wrote the date on my new battery with the eclectic pencil also so that I would know at a glance how old it was this time.

usually there is a trickle charger on them so there is always a charge, but when they are on the floor..ie Wallyworld....that's an invite for a lawyer to make money,,,,,zappa

paved parking lots in summer are great for frying batteries, heat rises to under the hood and because it's sound proofed
All that has to happen is the rising heat ( on the bottom of the battery) melts the lead and then shorts not giving you the X amount of volts

one of my Agri Engineer Profs did a study on battery life around covered building and battery longevity . A car port shading overhead sunlight extended battery life for 3 years.
Come to think of it; I think his real purpose was to drive around and meet single prairie girls and have return visits every summer. His slide lecture sure had a few Young ladies leaning over the hoods...checking the batteries. ( it was one lecture every year that was a DO NOT MISS)and the seats were always full.