Hey guys,

Quick question: does using a cigarette lighter for large durations drain the car battery?

Reason I ask, is because I recently purchased the below FM transmitter - which connects to the cigarette lighter port, and allows me to play audio from my phone (via bluetooth) or USB stick. Upon my first use (where I was listening to music through it for an hour), I returned later to my car that day and when I turned the ignition it really struggled to start.

https://www.amazon.co.uk/Upgraded-Nulaxy-Wireless-Bluetooth-Transmitter/dp/B01MZADLK8

Is it possible that constant use of the cigarette lighter can drain the battery?

Many thanks

Edit: One important thing I failed to mention, was that I didn't leave the FM transmitter connected when I left the car. I made sure to unplug it and put it away. So I guess I should have asked whether it has the potential to drain the battery when using whilst driving?

Eventually it will ,but as the device uses a very small amount of current it would probably take a long time to do so. Any thing internal/external that uses the battery will drain it a little. Using it for an hour I suspect will be fine.

mine is used 24/7 with my dash cam and have never had a problem

Its ok if your running the engine but it don't last long just off the battery

10 hours ago, Tywin said:

Quick question: does using a cigarette lighter for large durations drain the car battery?

Quick answer: It depends !

Sorry, but 'tis true, it depends on how much current your equipment is drawing, and on the condition of the battery.

For example, a 60AH battery in good, new condition and fully charged will supply 100mA to a device for at least a few hundred hours (a week or more) without any problem. And still start the car fine.

I would hope that an FM transmitter, when put into standby so its display at least is out, would draw well under 100mA. I think I measured one at about 40mA.

But if your battery is getting a bit knackered, then drawing 1A for a couple of hours (parking lights on, for example), might take enough out of it so it could not start the car.

Built in equipment like alarms and the remote locking receiver are always on and drawing a few 10s of mA, and this load can flatten an ailing  battery in a fortnights holiday away, without load from add-on goodies.

So, overall, if your car struggled to start after just a few hours, then either the FM transmitter is drawing a silly amount of juice, which would make it warm to the touch. Or yer battery is pretty well shot.

I uses the cigarette lighter socket to power my dab amplifier only my stereo but left it plugged in when on holiday for a fortnight and when I got back the battery was as flat as a pancake 

Thank you for the responses, everyone.

One important thing I failed to mention, was that I didn't leave the FM transmitter connected when I left the car. I made sure to unplug it and put it away. So I guess I should have asked whether it has the potential to kill the battery when using whilst driving?

13 minutes ago, Tywin said:

I guess I should have asked whether it has the potential to kill the battery when using whilst driving?

No, I am sure it can not affect the battery while driving. The normal loads the alternator has to cope with are much, much bigger than any car FM transmitter.

 

2 minutes ago, Tdci-Peter said:

No, I am sure it can not affect the battery while driving. The normal loads the alternator has to cope with are much, much bigger than any car FM transmitter.

 

Brill. Thank you, Peter. Got a long journey ahead of me tomorrow and it's made me feel better that I can load it with some audiobooks :-)

Just remember that for any battery to recover from discharge it should only go down to HALF it's capacity, so for a 60AH battery, 50% charge=30AH, so even 100mA will drop the battery below this if the car is unused for just over 12 days...

Most cig sockets are de-powered by the car anyway when the engine is off (after a time or when certain battery conditions are met)

 

Hi as I have suffered the same problem I was told that if I got a mini blade piggy back fuse and put it into F100 then wired the positive wire it will turn on and off with your ignition hope this helps