I have a 2012 Ford Fusion SE. My problem is that my dc power outlets (cigarette lighter) are on continuously. I was charging one of my cell phone battery packs and as I unplugged it I noticed that the light on my dc to USB adapter was still lit, meaning that power was still on the line from the battery pack.

I was wondering if I left that plugged in, will it compensate for the constant drain of something small like a radar detector?

  • 2
    Welcome to Mechanics SE! Will what compensate? I don't get the question. Anything plugged in will drain the battery, it's just a matter of how fast it drains.
    – JPhi1618
    Dec 1, 2015 at 13:38
  • Also, are you sure it isn't just on for a period of time then shuts off? In some vehicle (not sure on the Fusion), the cigarette lighter will only stay hot for 15 minutes after your vehicle is shut off. This is controlled by the Body Control Module (BCM), just like the radio, wipers, and windows may work after you turn off the key until you open a door. Dec 1, 2015 at 16:14
  • They do not shut off after 15 minutes. I have accidentally left stuff plugged in before and it was still on when I got back into the car.
    – user13442
    Dec 1, 2015 at 19:42

1 Answer 1


No, the system has no ability to compensate for drain, however small, if the engine is not running. Therefore I would recommend removing anything from the power outlet if the car is parked up. Even the smallest drain (such as an interior light left on) will eventually drain the battery and prevent the car from starting.

  • But what about devices such as solar panels that plug into the outlets stating that they will compensate for a small drain? (Example: gandermountain.com/modperl/product/… )
    – user13442
    Dec 1, 2015 at 19:45
  • A solar panel is providing, not drawing charge. Dec 2, 2015 at 9:24
  • Yes, a solar panel charger should compensate for a small drain, if that is what you are asking. Dec 2, 2015 at 15:49

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