They'll last longer if you just take care of them. What kills them is allowing the battery to discharge. When it discharges too far, sulfate collects and forms a coating on the lead plates. The coating impedes the chemical reaction, making it difficult or even impossible to charge the battery. I just make it a habit during the offseason to take all the batteries out of the toys and tools (boat, seadoo, lawnmower) and put them in the garage when i do my winterization. Just charge them once a month and they last so much longer. I'm on my 4th season on the cheapo autozone duralast in my boat and its still going strong. Having to replace one battery every year isnt a big deal, but it gets expensive when you have so many. Taking that small amount of time every month can end up saving a significant amount of cash. That money is better spent on gas instead of just flushing it down the toilet.