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Does cigarette lighter adaptor drain car battery overnight?

B

Bill Latshaw

Lurker
Hi.
I bought a car cigarette lighter splitter to plug in 2 devices. With it plugged in, with no devices attached, will it drain the car battery. The only thing on, is a tiny red LED on the splitter.
Thanks for your help.
Bill NJ
 
It's politically incorrect to call them "cigarette lighters" ... now they are "accessory ports". ;) :rolleyes:

If the light's lit, then there is a drain on the battery. But, that little LED is using only a fraction of a watt and with nothing else plugged in, there should be no additional drain. I leave mine in all the time, but I use the port in my car that disconnects power when the ignition is off.
 
It depends on the vehicle. In most late-model cars the power outlet(s) in the dash/console are ignition-switched and will not operate unless the key is in either the run or accessory position. You can check the owners manual for your particular car to see how the outlet behaves.
Some newer cars will have a "retained power" system where the accessory circuits will remain active for a set period of time after turning the ignition off, maybe 30-60 minutes or until the car is locked. Again check your manual.
As for the potential drain with the adapter connected, I agree it wouldn't be that much but I'd still unplug it if in fact the circuit does remain active. There is already a small parasitic drain from all the electronics in the vehicle, no need to add to it.
 
A typical car battery has a relatively huge storage capacity so something like a little LED indicator light is drawing an insignificant amount of power. The amount of power it's using is pretty much the same as what is being used to save your radio station pre-sets.
Just some typical numbers to gauge things by;
-- a typical 3mm LED, like the one that's commonly in devices like you have, uses about 17mA
-- a basic (lower end) car battery will have at least 45Ah capacity, or for comparison 45,000mAh,
So don't worry about it.
 
Like others said, no problem, the battery is big enough to power the anti-theft system for weeks.

And cars usually cut off the power to the cigar lighter port when you remove the ignition key.
 
Like what others have said your completely fine having it attached. I tend to leave mines from time to time on the port as well
 
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