7 Amp 100 Watt 12 Volt Solar Power Charge Controller With Digital Led Display : The Solar Charge Controller is designed to protect batteries from overcharge and excessive discharge when being charged by a solar panel device. The controller functions to automatically assure the battery is fully charged and keep the battery fully charged without damage to the battery. A solid state electronic device needing no maintenance. It utilizes the latest in solid state MOSFET switching for efficient and reliable operation. The controller provides three colored LEDs to indicate the status of the solar panel and battery: Green LED: On indicates the battery is fully charged. Yellow LED: On indicates the battery is charging. Note: It is normal for the Green and Yellow LEDs to flicker back and forth during normal operation. Red LED: On indicates the battery level is low.