Gallagher S20 Lithium Solar Fence Energizer. Powers up to 12 miles / 40 acres of single wire fence. It is a compact, portable, fast charging and long-lasting solar fence energizer that's designed to put more power in the hands of the customers. It has an internal lithium battery, a highly efficient solar panel, intelligent adaptive energy control and robustconstruction that come together to provide unparalleled performance and reliability. It is protected with a 3-year warranty.