Smart Car- How to open the door to charge the battery?

So my grandmother sent me her smart car for christmas and I am still learning everything.. my whole fam is trying to figure this out haha.. how do you open the little black circular door where you charge the car? thanks so much~!|||The biggest SMARTASS is you. The Smart car is a 3 cyl diesel and only has a plug for the block heater. the motor is in the back and you won`t believe where the windshield washer fluid goes. Keep it plugged in my friend. When the fuel gage says E and you left it plugged in all night, you still are not going anywhere, It will be out of that old dino fuel called diesel. You can unplug it now. And you thought Grandma was a dummy. Down the hallway, open powder romm door and look in the mirror.LMFAO all over 3 times on the floor. Plug in a smart car? Should plug in the new owner. Oh and just so I am not that rude, the little black circle you are trying to open has a lever on the floor beside the drivers seat to open it, Called a fuel door. Inside that door is a fuel cap (gas cap for simple peolpe). In the opening you will insert a nozzle that comes from a pump that says diesel or gas on it, Think that you could possibly find the owners manual in the glove box or maybe go online and find out even more info?|||Sorry, You really have to get some books or manuals as that car is Totally different designed and things are never where anybody would think. Talked to a few friends and was amazed about story's.|||I really dont know how but i know some sites that i think can help you about this one. I also got alot of information on that site also.|||Normally they give IQ tests before you can buy a Smart Car. If you are not smart enough you cannot get one. This is why you cannot open that cover.|||uh smart cars were gas powered i thought