Depends on the charger but either effectively zero or considerably less.
People get pissy about it, but think of electricity like water. Having a longer pipe is a negligible amount of water if the faucet is still off. And the faucet can only turn on if your device completes the circuit by being plugged in (and doing the appropriate handshakes)
That said, some chargers will consume a negligible amount of electricity to actively listen for a device. Think of it like the water in your toilet. Every so often enough evaporates or leaks that you hear it run a bit to refill. But mostly it is nothing until you flush.
I use a short lightning cable to plug my phone to my car for carplay. I just leave it plugged into the usb port (without the phone) when I’m not in the car. Do you think it’s slowly draining some energy from the car battery?
The cables themselves do not use power. It is the brick.
Your radio being off would not push any power through a cable. Also your cigarette lighter being off would not push any power. Which is why plugging it in won’t do anything.
To continue the metaphor - your water is turned off. You can’t use up water that isn’t there.
The reason the brick uses power is because it is available 24/7 for you to plug something in - and when you do - it can ask that device how much power it wants - does it have fast charging? Etcetera.
Thanks. About the cigarette lighter - my dashcam plugs into it but I always unplug it before I turn the car off so never noticed if the camera turns off along with the car. If it does, does that mean I can just keep the dashcam plugged in and it won’t draw power even though the camera is connected on the other end? Or does closing the circuit mean it will start drawing power?
Depends on the charger but either effectively zero or considerably less.
People get pissy about it, but think of electricity like water. Having a longer pipe is a negligible amount of water if the faucet is still off. And the faucet can only turn on if your device completes the circuit by being plugged in (and doing the appropriate handshakes)
That said, some chargers will consume a negligible amount of electricity to actively listen for a device. Think of it like the water in your toilet. Every so often enough evaporates or leaks that you hear it run a bit to refill. But mostly it is nothing until you flush.
Here’s an article on it, in case you wanted to know how to go about verifying it for yourself.
As an electrician I approve this analogy
I use a short lightning cable to plug my phone to my car for carplay. I just leave it plugged into the usb port (without the phone) when I’m not in the car. Do you think it’s slowly draining some energy from the car battery?
The cables themselves do not use power. It is the brick.
Your radio being off would not push any power through a cable. Also your cigarette lighter being off would not push any power. Which is why plugging it in won’t do anything.
To continue the metaphor - your water is turned off. You can’t use up water that isn’t there.
The reason the brick uses power is because it is available 24/7 for you to plug something in - and when you do - it can ask that device how much power it wants - does it have fast charging? Etcetera.
Thanks. About the cigarette lighter - my dashcam plugs into it but I always unplug it before I turn the car off so never noticed if the camera turns off along with the car. If it does, does that mean I can just keep the dashcam plugged in and it won’t draw power even though the camera is connected on the other end? Or does closing the circuit mean it will start drawing power?
If the camera turns off when you turn the car off then you’re safe to keep it plugged in.