Dual Purpose batteries provide enough power to start your boat engine and supply additional power for operating trolling motors. They are great solution for boats with limited space. Dual Purpose batteries are designed for marine usage only and not for use with road vehicles (i.e., cars, trucks, buses, RVs). Deep Cycle batteries are suited for both marine and RV usage. They are designed to power the onboard electronics in your boat (i.e., fish finders, GPS, electronic trolling motors) and power your stove, microwave, radio, television, emergency back-ups and other electronics that are not connected to shore power on your RV. Dual Purpose and Deep Cycle batteries are not recommended for use as a starter battery in RV applications. Deep Cycle batteries are also great anyone fishing on a lake for long periods of time – and they provide peace of mind for RV owners who enjoy prolonged dry camping or just extra time away from home.