The best way to assist in prolonging the life of the battery would be to keep it fully charged. Doing so will decrease the risk of sulfation. Sulfation is what deteriorates the plates within the battery. Once the plates have deteriorated, it will decrease the amount of charge the battery can hold, thus shortening its life. Periodically charging it using a good quality, electronic battery charger will cycle it through a charging process that will keep the battery cleaner, fully charged and healthy.