2004 Chevrolet Tahoe, Battery Draw for USB Port

Hello. I've got a 2004 Chevy Tahoe. I've removed one of the 12 volt receptacles in the front console to replace it with a USB charging port. The new port has a feature that shows the voltage of the battery on the face of the port, which is shown whether a USB plug is inserted or not. Because the Tahoe's 12 volt ports are always live, even when the key is out of the ignition, I'm wondering whether the draw from the battery required to illuminate the volt reading would ever be enough to kill the battery over time. I suspect it's a very light draw, but in cold New England temps I don't know if it would be something that hurts the battery life over time. Any thoughts would be appreciated. Thanks!

If you have a multimeter, you can measure the current draw with nothing plugged into the port. Disconnect either the power or ground wire and put your meter leads in series. Set your meter to DC current and see what you get.My ex once told me I have a perfect face for radio.