Dual Purpose batteries are designed for applications requiring a high burst of current for a short period of time to start a boat engine, generator motor or devices with high amp draw. Then they can double as a power source for your electric devices for your boat or RV. Dual Purpose batteries are a solution for boats with limited space. 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. 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. Dual Purpose and Deep Cycle batteries are not recommended for use as a starter battery in automotive applications.