The Vevor 20W 12V solar panel battery charger maintainer is designed to keep 12V batteries charged and maintained using high-efficiency monocrystalline solar cells. It features an external intelligent MPPT controller that automatically stops and resumes charging to help protect battery life. The IP67 waterproof construction supports reliable outdoor use on cars, boats, RVs, motorcycles, trailers, and more. An adjustable 0°–60° mounting bracket allows better sun exposure, and the included extension cord and connector cables make setup simple.