Many owners say that if they are visiting a friend's home and need a charge, they rely on dryer outlet if available. In case dryers are away from garage or a place where car is parked, I am assuming that these folks are using an extension cord. What are the specificaitons and links for some of these extension cords? I am wondering if on road trip, we should also keep such an extension cord along with UMC for just in case. This allows us to get power from many homes at a faster rate than say 110 V.