When your quad sits a lot , especially the new electronic ignition, computer controlled ones they should be kept on a battery maintainer. The small trickle used by the electronics even when the ignition is off will drain the battery. SLA and AGM batteries also always have a bit of self discharge so the combination of the electronics and self discharge means they must be kept up topped up. They do not like to be deep discharged and quickly lose capacity if they are .. Totally flatten either type and you are pretty much guaranteed the battery is toast.. A small maintainer is a lot cheaper than a battery and will eliminate the buying of a new battery every year. I have one on my truck, another on my quad and a third on my riding lawnmower.