I bought our two 6V AGM batteries from Sam's Club in April 2015 and they are still doing well, but the past 3 years have been minimal usage given we were doing world travel and then COVID. It's more of an "age" thing in our case. The plan is to continue using them and see what happens. There is always a Sam's Club somewhere else to buy them from.
As many here know, I am a miser to a fault. Hey, I replaced my original 14.5 year old tires just this year. I was surprised to see their production date code 5006. (50=week50, 06=2006) My chassis was built in April 2007.
They just started to crack as seen here, but no cracks in between the threads.
