If you are purchasing the battery made by GTO/Mighty Mule they only have a one year warranty and the life expectancy is 3 years. GateCrafters.com has the same voltage/amp hour rated battery that comes with a 5 year prorated warranty. The expected life span is 5 years and if it dies before then you only pay for the length of the 5 years you have used and receive a new battery as a replacement. For example if the the battery dies 36 months into the 60 month (5 year) pro-rated warranty we would take the price of a new battery, divide it by 60 and multiple that times 36 [Example: ($34.94/60)*40=$19.81, your pro-rated battery price]. This would be your pro-rated price on a new battery. http://www.gatecrafters.com/product_detail_2641.aspx