what can you use this for and how many...
what can you use this for and how many volts is it
Laptops connect directly to the USB port. This unit generates 12 volts. Most phones/camera/tablets work (optionaly)with a 12 volt battery (Car/RV/Marine). Check to see the voltage, wattage, and storage/isolator/inverter capacity. Usually presented as Amp hours.
Make sure, if you're going to rely on any of these products, that they are set up for your use.