900 Trail- which battery is the best upgrade?

So my brand new 900 trail with 9hrs on the clock is back at the dealer with battery problems. The stock Polaris battery won’t hold a charge and I don’t want another crappy Polaris battery installed. So what’s the best battery of choice? I want this next one to last a good few years so spending a few extra bucks is not a problem! I was told a deep cycle marine battery is best. Any advice?