I have a car stereo head unit that I'd like to repurpose as a radio for my garage. Given that, I'm looking for some kind of power adapter / transformer that I can plug into a wall outlet and splice into the stereo harness. Presumably this would need to convert from 120VAC to 12VDC, but I'm not sure what I'd need as far as amperage goes. If it's relevant, the stereo was on a 10 amp fuse when it was in the car.

I've seen people use computer power supply units, the big 350 W guys, but that seems like major overkill here especially since I'm only looking for the 12v and wouldn't need the other wires from a PSU like the 3.3v and 5v lines.

  • Depending in what part of the world you live where you can get one, I have used a car battery charger to do this. 10A is more than enough to power a head unit. 5 amps will probably do.
    – Moab
    Apr 30, 2016 at 17:31
  • To add to @Moab's comment, using a battery with a battery float charger on it would work perfectly for your needs. It would keep the battery charged, plus you wouldn't have to worry about the charger not being able to provide enough power for the stereo. Apr 30, 2016 at 21:42
  • The PSU is the safe way to go and its portable. You can get them cheap these days or even free. Just ask around.
    – race fever
    Apr 30, 2016 at 21:47
  • @Paulster2 floating a car battery while using a proper float charger will make the car stereo go well .BUT if the stereo draws more than the charger when its playing loud you are draining the battery .When the stereo is not drawing much like when it is in standby the battery will charge .This means that the car battery is charging and discharging or cycling .When there is significant cycling the car battery wont last as long as it would in its float life .If your float charger is grunty things will be OK.
    – Autistic
    May 1, 2016 at 4:05
  • @joseph Your posts asks for an adapter. What country are you in? Different countries have different wall outlet connector types. For Example: in the US a wall outlet would be the NEMA 5-15 connector type. May 2, 2016 at 22:49

1 Answer 1


Your car Audio should work well in your garage .Mine has been running for 17 years now .The 12 V DC power supply needs to be rated for the job as others have commented .If you use a switchmode power supply which is more common these days you may get noisey radio reception due to the crud that these supplies put out .Placing the Antenna on the roof will minimise this potential problem .If you use an old school linear power supply your ability to get distant stations should be excellent.The old school linear power supplies that are designed for radio telephone equipment would perform well.I used a transformer and bridge rectifier and filter capacitor for one of my installs .I used much more filter capacitance than usual because car equipment is designed to filter alternator whine and does not filter power hum very well .A lot of modern car audio equipment wants to be connected to 12V all the time .You will notice that when you change your car battery the radio forgets its stations.If your 12V is going to be on all the time then your power supply should have a low standby current or you can use two supplies .Small one for the memory and large for the radio .

  • Is there some kind of a wall adapter that can be used or do you need to hunt for the various wires and connect them to a nema 5-15 plug....well, nema 5-15 would be a US standard so....not sure where the OP is. May 2, 2016 at 22:48
  • @ DucatiKiller...The OP lives in New Zealand .A wall wart would be unlikely to produce enough current.
    – Autistic
    May 2, 2016 at 22:51
  • Gotcha, I was reading your post and since I'm not as electrical friendly with a huge knowledge base such as yours it's a bit Greek to me. I wouldn't be able to do it based upon your post due to my lack of knowledge. That being said, I'd like to take some of my old car stereos in my garage and put them to use....in my garage. Is there way you can simplify and break your answer down into a general DIY howto? If I'm asking for too much, I understand. TY. May 2, 2016 at 22:53
  • Thanks, @Autistic for the response. Good point about the necessity for constant power. Talking about switchmode vs linear power supplies is definitely over my head as far as electricity goes, can you elaborate more? Do you think something like this might work?
    – Joseph
    May 3, 2016 at 1:41

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .