Car Talk —— Today’s power ports — or yesterday’s "cigarette lighters" — drain too little power to worry about devices plugged in for long stretches

With all these things we are plugging into our lighter sockets these days — phone charger, GPS, radar detector, you name it — we end up with these lighter-socket plugs sitting there all the time with glowing LEDs on them. My question is: Do these LEDs draw enough current to pose a threat to my battery’s life? Should...