Spyder batteries come in two forms...dry charged and factory charged. The Spyders were originally shipped with dry charged batteries, but problems with the dealers failing to allow time after filling for the glass mats to absorb the acid, and failures to charge them sufficiently before laying them on their sides and installing them, led to numerous premature failures. It is my understanding that they now come factory prepared in the Spyder, but replacement batteries may still be dry charged. The dry-charged version should have a longer shelf life. If you want the best battery available, I would consider a lithium-iron battery. They are lightweight, durable, and don't lose a charge sitting idle (except for parasitic losses).