I have now had my AGM Intimidator Battery from Woodmizer in my LT70 for a little over 9 years. Still going strong.
Have a couple in my pickup that are several years old, either the skidder or the buncher have a pair also - all doing fine after several years. You get what you pay for in batteries for sure.
I had one in my fishing boat for trolling motor and it lasted 7 years. I may have killed it prematurely by not charging it a few times after fishing because it was stored in a temporary location with limited access to electrical outlet. Definately got my money's worth out of it.
Anecdotal varies from 3-4 years up to around 9-10. My tractors OE battery was an Interstate wet cell that made it from 2010 when new, then until ~9 years later. My Vespa Scooter has a sealed acid battery from fall 2018 that just died. I'd failed to put my tender back on it and the electronics sucked it to death. Google will say 4-7? My 2015 Ford F-150 has the OE, sealed acid battery and if left setting a couple weeks it is a slow cranker. I have a sealed Chromebattery in my Mule UTV thats about 10 years old now. I've also had them die in 2 years on other motorcycles, most go ~ 5-7 yrs..
Riding mower batteries suck no matter which and don't last long IME.
The longer an acid battery stays discharged the faster it sulfates and dies.. Meaning loses the capacity to hold sufficient charge levels because of the sulfur oxides (iirc) glazing up the anodes and cathodes i guess. Anyway it can be boiled off with pretty good success by hot charges. I use battery starter 200amp mode for a minute or two any time a battery comes into sick bay to get balanced off with fluids and electrons.
Deep cycle batteries for trolling can come back from many deep discharges but standard auto starting batteries cannot. Deka's made by east penn have been the most amazing comeback case i have experienced. Ive defribulated many ovet the years but none as flatline DEAD as those dekas several times. No idea why.
6 years is typical on Optima red tops in my experience. The biggest advantage to me is no corrosion on the terminals, and they can take vibration better than conventional. They are also safer in an accident as they don't have liquid...
I got two Autocraft Platnium AGM batteries from Advance Auto Parts Memorial Day Weekend of 2016. One just quit, the other one is still going strong. I'd say expect roughly 5 years depending on environment and usage.
I only use agm in the bikes. They take the vibrations better.
When not being used all are on battery tenders.
Tip of the day: I recently bought a new sealed gel battery for my Vespa. I began looking on Amazon then found the same battery on Walmart.com cheaper by a tad. I then looked on the Chrome battery website at the same battery yet again and it was cheaper yet so I went to checkout- after seeing the empty box for a discount code I googles that and put in the box getting another 15% off, then I went back to checkout and was asked if I wanted to use "Amazon Pay" so I clicked yes and then I saw the total had no sales tax. Wowee! I got it cheaper than their own Amazon store or Walmart. com both of which I pay sales tax then the 15% plus still had free shipping.
Made in Thailand, it's neat given the gizmo on top that recorded the date hooked up, the voltage, and more in a window made into the top of the battery label. $29.
Vibration's one battery aspect on two wheels, not having acid spilled on ones bodies is yet another. For years BMW and some other mfg.'s persisted in using wet open batteries. Even more important is my head which gets a helmet, plus boots, plus a real jckt, gloves and britches that keep my skin intact... I hope... ;D
Odyssey has been good for me but pricey. Chinese Motobat is popular last few years. I've had mixed anecdotal results from them.
Tenders: I stopped buying Battery Tenders- the brand name- as I've had to throw several away. Still have several but now like Marinco or another brand I can't spell? CTEK? as they do more stuff.
I believe the AGM Battery is much better than a regular automotive battery . . like everyone says they hold up to all of the vibration of a sawmill
I'm probably setting myself up to purchase my 6th battery in the last couple of months. When we bought our Lt-50 used, several years ago, it had the original AGM battery in it from 2016. One day three or four years ago, the mill failed to start. I bought another AGM battery for about $200 and installed it in the mill. My Kubota M7040 tractor's battery bought the farm at about the same time. I charged the dead battery that came out of the mill and installed it into the tractor. That 2016 battery is still in the tractor.
Generally, it is the summer heat here that smashes batteries.
A couple of weeks ago, I bought three batteries. I put an AGM in my Bronco. It was $150 and has a one-year warranty. I put lead acid batteries in my wife's car and in our old Jeep Cherokee, they cost the same but have three-year free replacement warranties.
I have only had one Optima and it didn't last as long as the East Penn lead acids for me anyway.
The Carquest brand lead acid batteries that were made by East Penn were excellent. The one in my mill must be pushing 10 years old. Same battery in my skid steer, it was about 8-9 years old when I replaced it, and as it turned out here was nothing g wrong with it. So I put it in my skidder that needed a battery. Now Carquest carries Diehard batteries, I don't know who makes them or how good they will be.
I say all of this, only to make the point that I don't know what an AGM would benefit me.
BB: Napa and Batteries Plus are made by east penn.