- #1
everybest
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Anybody know how these things work? I think they heat up even when the car is turned off; does that mean it doesn't use any batteries?
How do car cigarette lighters work?
- Thread starter everybest
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Discussion Overview
The discussion centers around the operation of car cigarette lighters, exploring how they function, their power sources, and variations across different car models. Participants share personal experiences and technical insights regarding the heating mechanism and electrical configurations.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- Some participants believe that cigarette lighters heat up even when the car is off, suggesting they do not use the car's battery.
- Others clarify that lighters typically use the car's battery and only function when the key is in the "Accessory" position, though some cars may have different configurations.
- One participant mentions using a lighter to charge a cell phone when the car is off, while another states their charger does not work under the same conditions.
- There are claims that the functionality of lighters and accessory outlets can vary significantly between different car models and years.
- Some participants propose that the heating mechanism of the lighter is similar to that of a bar heater, converting electrical energy to heat energy through a filament.
- Another participant describes the lighter's operation as a coil that heats up when connected to a power source.
- One contribution mentions a thermostatic system that causes the lighter to pop out once it reaches a certain temperature, sharing a personal anecdote related to this feature.
Areas of Agreement / Disagreement
Participants express differing views on whether cigarette lighters can operate when the car is off, with some asserting they can and others stating they cannot. There is no consensus on the specifics of how the lighters work across different vehicles.
Contextual Notes
Variations in car wiring and configurations are noted, with some participants suggesting consulting technical manuals for specific vehicles. The discussion reflects a range of personal experiences and assumptions about the functionality of cigarette lighters.
- #2
belliott4488
- 661
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No - it does use the car's battery - that's why it only works (in most cars, anyway), when the key is in the "Accessory" position so that the lighter is powered. I don't know if maybe some cars are wired so that it's always connected. In any case, it definitely doesn't work if your battery is dead.
- #3
Dr Transport
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Mine works when the car is off, I use it all the time for charging my cell phone.
- #4
everybest
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I actually don't have a lighter myself, and but my cell phone charger doesn't work when the car is off. My friend says his lighter works when the car is turned off though.
- #5
belliott4488
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I don't even have a cigarette lighter any more - I have 12V accessory outlets, and now that you mention it, I think they might work in my 2006 Honda Element with the key out, but in my 1997 Honda Prelude, I have to turn the key to the accessory position to charge my cell phone.
I wonder if it was considered dangerous to have "live" outlets when there were hot little ignition devices plugged into them, but convenient to have them now that we're more likely to charge cell phones than to light up a smoke. (?)
I wonder if it was considered dangerous to have "live" outlets when there were hot little ignition devices plugged into them, but convenient to have them now that we're more likely to charge cell phones than to light up a smoke. (?)
- #6
Shahil
- 116
- 21
It's purely car dependent and works in the same way as your radio does. I wired my radio so that it works even without a key whereas most only work when the key is in the ACC position. My lighter though (I have a Fiat) doesn't work if the car is off. I'm guessing you can just refer to the complete manual for your car (not the one that comes with it! A technical one) and then change how it acts if you desire. I'm not sure what it will do for the warranties though 
- #7
Integral
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My 06 Chrystler has 1 outlet always on, another switched. My other car can be configured either way, depending on which slot the fuse is in.
- #8
Shahil
- 116
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Nobody here actually has addressed how these actually work! I'm guessing it works similar to a bar heater at home - electrical energy to heat energy via those filament type things inside the lighter. Quite simple really!
- #9
K.J.Healey
- 622
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Yes, it is 12v. The cigar heater, you push in so the ends make contact with the leads, it goes through a filament wire that heats up due to the electrical resistance.
Some cars are on the battery, through a fusebox. Others are on the accessory circuit, where they only work if key is on.
Some cars are on the battery, through a fusebox. Others are on the accessory circuit, where they only work if key is on.
- #10
binzing
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The bloody thing works like a coil! Hook up a wire to a 9V battery and it will get hot, there's your answer.
- #11
Danger
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They also have a thermostatic system that trips a spring to pop them out once they're hot.
I remember when I took a nap in my '66 Falcon. I awoke in serious pain, only to realize that my knee had been pressing the lighter into its socket. Since it couldn't pop out, it heated up to the point that the plastic knob had melted itself into the fabric of my pants.
I remember when I took a nap in my '66 Falcon. I awoke in serious pain, only to realize that my knee had been pressing the lighter into its socket. Since it couldn't pop out, it heated up to the point that the plastic knob had melted itself into the fabric of my pants.