Car audio Bluetooth adapter question

February 24, 2023 10:12 AM

Is there a car audio Bluetooth adapter that I can leave plugged in 24x7, inside the center console, without killing my battery?

I have a 2010 Subaru Outback. It offers an Aux jack and a 12v power port, hidden inside the center console box.

I would like to leave a Bluetooth adapter plugged in there 24x7 without killing my battery. (I'm not interested in replacing the entire stereo right now, as nice as that would be.)

Is this possible, or is my understanding of car batteries incorrect? (My money is on the latter....)

Can anyone suggest a manufacturer or adapter?

Thanks!

posted by wenestvedt to Technology (8 answers total)

Check if the 12v port loses power when you take the key out of the ignition. For most 12v ports, this is the default behavior. If yours only has power when the car is running, you're good to leave the bluetooth adapter plugged in with no risk to your battery.

If the 12v port is constantly powered (some are) then there's some risk you could drain the battery when you're not using the car, but that will depend on how much the adapter draws and how frequently you drive the car.
posted by RonButNotStupid at 10:19 AM on February 24, 2023 [3 favorites]

Our Outback of similar vintage kills power to the 12v cigarette lighter in the center console when the ignition is off. The Bluetooth adapter in there is only on when the car is on.
posted by zamboni at 10:19 AM on February 24, 2023 [2 favorites]

Probably the cigarette adapter cuts its power when the car is off. But another fancier alternative would be to replace the stereo head unit with something more modern with Bluetooth and maybe wireless CarPlay/Android Auto. They’re like $500 so not cheap but IMO a great upgrade if you plan to keep the car a while, especially if you’re in that generation of Subaru entertainment system where it’s got a touchscreen but you can’t see it during daylight.
posted by aubilenon at 10:39 AM on February 24, 2023

Best answer: I have a 2010 Subaru Forester with the same ports in the center console. I plugged in a three cigarette outlet adapter and have a wireless MagSafe charger, a SiriusXM radio, a Garmin GPS and a bluetooth adapter all running off the same port power port.

I haven't had a problem if I take the key out of the ignition. I leave the light switch on which is fine unless I forget to take the key out of the ignition. Then the lights stay on and kill the battery.

Other drivers have killed the battery twice in the last couple of years, one because he sat in a parking lot all day listening to music, and the other because he forgot to take the key out of the ignition when he parked the car. But both of those were probably because the lights were on, not because of the extra load of the devices.
posted by rsclark at 10:42 AM on February 24, 2023 [1 favorite]

Oh, I forgot. I'm also powering this mixer so I can hear music from the bluetooth adapter, the SiriusXM radio and a guest phone (via lightning to Audio adapter) through the aux port. Yes, I am a nerd about this!
posted by rsclark at 10:48 AM on February 24, 2023

Best answer: I use a Tunai Firefly for this in my pretty old Honda Odyssey. It works quite well.
posted by cmm at 11:44 AM on February 24, 2023 [2 favorites]

2015 Jeep and I have leave my 12V Bluetooth adapter in all the time. It's also got USB ports so I can charge my phone. If you have a 12V phone charger adapter, see if it stops charging your phone when your car is off. If so, then the power gets cut, and leaving in the Bluetooth adapter won't run down your battery either.
posted by Saucy Possum at 6:11 PM on February 24, 2023 [1 favorite]

Response by poster: I bought a Tunai Firefly (not the Chat model), and it works well. Thanks for the suggestion, cmm!

My 2010 Outback does, indeed, kill power to the 12v port in the center console box (under the driver's elbow), so that's good.

The wireless (Bluetooth 5) connection seems strong even with the lid shut and a stack of CDs in the console (which I would imagine aren't very radio-transparent!), whether I put my phone in a cup-holder or into the phone holder up on the dashboard.

I almost bought rsclark's suggestion, but I don't want to make calls while I drive, so the button & speaker/mic weren't necessary.

Thanks, everyone!
posted by wenestvedt at 11:58 AM on February 28, 2023 [2 favorites]