Here you can get some really suspicious cheap car batteries, i would not go for one of those.
On my Yamaha quad ( the 660 CCM raptor ) the factory battery died pretty fast too after a couple of years, and it was not like i was driving it all the time / every weekend.
When it come to car batteries i have only tried to change one once, and that was my Opel Kaddett GT which i was #2 owner on and got it when it was 5 years old.
Put one new engine room battery in it and 2 batteries in the back along with capacitors and subwoofers / AMP's and then that boot was full and the car a few 100 Kg heavier.
My Mitsubishi L200 pickup had 2 batteries, one for starting and one for ACC stuff i assume, but i never changed any of them though the Audio in that car was also above normal in wattage.