The 6 LED lights indicate charging status and battery conditions. These functions are described below: Solar Power Indication (POWER LED-red) ON: Indicates solar panels have proper connection and solar power source supplied. OFF: No power available or insufficient voltage to active charge controller. Charging status (“CHARGING” LED-blue; “CHARGE COMPLETE” LED-green) CHARGING LED: ON indicates the battery is charging, virtually all the power from the solar array pass through to the battery. OFF indicates the solar panel voltage is too low (insufficient daylight). CHARGE COMPLETE LED: ON indicates full charge reached, a small “FLOAT” charge continues to optimize battery when needed. OFF indicates the full charge has not been completely reached. Battery conditions GOOD LED: ON indicates the battery voltage is over 12.5V, usually indicates when the unit is charging. FAIR LED: ON indicates the battery voltage is between 11.5 to 12.5V and needs charging. LOW LED: ON indicates the battery voltage is under 11.5V and needs charging. The LOW LED will be blinking if battery is unconnected to the unit.