Can not measure nearthe window, need sunlight Direct shot.
Controller connection steps:(the Last picture)
1. Connect the positive and negative poles of the battery , the controller will detect the battery voltage automatically ;
2. Connect the solar panel to the controller;
3. Connect the load as show , don't connect it reversely;
* Used to charge MP3 phones, pads or other controlled devices.
* Dual female USB ports, you can easily charge the device through the * USB charging cable.
* You can put the panel in the sun and use it to directly charge the device.
* Suitable for outdoor biking, mountaineering, hiking, camping, traveling, etc.
Solar panel power: 100W
Solar cell: Polycrystalline silicon
Solar panel size: 435*200*3mm
Solar panel operating voltage: 18V
Solar panel open circuit voltage: 21.6V
Solar panel short circuit current: 0.55A (Max)
Output port: Dual USB, DC5521 female
Product features: integrated 5V voltage regulator module
Product use: charge 5V devices such as mobile phones and sports cameras, and charge 12V car batteries such as cars and boat