The Speedrite S500 is a 0.5J solar energizer that powers up to 5 miles or 20 acres of electric fencing. The S500 includes an internal rechargeable 12 volt, 7 Ah SLA battery and fence leads. The typical output voltage is 9,800V on open circuits, 6,200V on a standard load 1000 ohms and 4,500V on a heavy load 500 ohms.