Cell Phone Car Charger Does The Car's Cell Phone Charger Take Energy Out Of Gas Or Battery?

Does the car's Cell Phone Charger take energy out of Gas or Battery? - cell phone car charger

I recently bought a set of accessories that the expenditure: (in the car, the "plug" thing that people use for mobile phone charger) receives energy from gas or the car battery? For if the gas, then I think back to my gear when the car battery, then it is good because you can always download again.