My odyssey pc680
Is 13 years old.And still working like new.
That's impressive!
I recall doing a problem in statistics about battery service life, I suspect your results is what is considered an 'outlier' or a 'rare event.' Regardless, it's a great service life.
Yuasa had a contest years-ago to find the oldest battery still in-service. I don't recall the exact rules, but the winner was an owner of a small Honda, I think it was a scooter. The battery was as I recall the original, and the bike was a 1960's product.
We recently replaced a hot water heater 240V that was in-service at my in-law's home since 1988. It still was working fine, but as an act of preventative maintenance it was replaced by another. That's 35 years! I think it had a 2 year guarantee on the label.
At our house, there is a porch light which has a 120V bulb and has lasted also 35 years.
Sometimes you get 'a good one.'