I had a AGM battery explode in my ATV (Honda 450).
http://castboolits.gunloads.com/show...ttery-explodes
I had got 4 years of use before it blew up.
I replaced that with another AGM battery ($100), only lasted two years, then would no longer hold a charge.
Since that one didn't last long, I figured I may as well go cheaper, so i bought a Chrome-Pro iGel battery on Fleabay for $40. It has a built in digital volt meter, kinda neat. That one is still going strong, I'm in my 3rd year with it, and started my 450 Honda in the below zero temps a few weeks ago, no problems. I see they are now $56 on amazon.
https://www.amazon.com/Chrome-Batter.../dp/B01BX9OYIU
I am rebuilding a small riding lawnmower this spring, I will probably buy another one of these for it, instead of using a cheap walmart LG battery