Mine's on the right-rear side of the fuselage and it has one of those flapper doors. I have the cable to plug into it in order to charge the battery. My question is: How does one go about charging the battery if it's low on juice? Obviously, I know to hook the one end of the cable to my car battery, and plug the cylinder end into the power port. But does one have to turn the master switch on in the cockpit or will the battery charge without the master switch on? Also, how long would it take to charge the battery if I'm using my car to do it?