Features:Durable, water-resistant and long lifespan.Light and thin, easy to use and carry.High conversion rate, high efficiency output, excellent weak light effect.Overcharge protection, reverse protection, DIY your backpack and teaching use.Little noise, high efficacy and low malfunction and suitable for outdoor activities like camping, fishing, hiking, etc. Specification:Bulb Wattage: 3WBulb Voltage:DC12VSolar Panel Voltage: 18VSolar Panel Wattage: 20WSolar Panel Material: Monocrystalline solar panelApplication: Car, boat, caravans, camping, fishing, hiking, etc. Controller:Features:1.Build-in industrial micro controller.2.Fully 4-stage PWM charge management.3.One-key setting,digital display, auto memory function.4. Reverse current protections, low heat productions.5.Build-in short-circuit protections, open-circuit protections, reverse protections, over-load protections. Specifications:Model: PWMBuck charge: 28.8VFloat charge: 27.4VUSB output: 5V/3AWorking current: 10ASelf-consume: <10mADischarge stop: 21.4VVoltage: DC 12V/24VMax solar input: <50VRated working current: ≤20ADischarge reconnect: 25.2VWorking temperature: -35℃~60℃Output voltage: 12V/24V Automatically distinguish voltage    　    　    Safety Instructions:    1.Make sure your battery has enough voltage for the controller to recognize the battery type before first installation.    2.The battery cable should be as short as possible to minimize loss.    3.The regulator is only suitable for lead acid batteries: OPEN, AGM,  GEL(It is not suited for nickel metal hydride, lithium ions or other batteries).    4.The charge regulator is only suitable for regulating solar modules. Never connect another charging source to the charge regulator.    　    　    System Connection:    1.Connect the battery to the charge regulator - plus and minus.it will show 1 ,if it detects 12V battery, 2 if it detects 24V battery.    2.Connect the photovoltaic module to the regulator - plus and minus.    3. Connect the consumer to the charge regulator - plus and minus. Package Included:1X 20W Solar Panel1X 10A Controller2X 3W Light Bulb