Whats a good 12v power supply to buy to bench test car audio?

[bigbswa]

Finally sold one of my tool boxes and now have space to set up a "bench work area" in the garage so I am looking for suggestions on a good 12v power supply to test car audio stuff. Especially amplifiers.

I want to buy something that can test out headunits and still have enough amps for high wattage car amplifiers.

Thanks

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[bubbagumper6 5,000+ posts]

Depends on your definition of "high wattage." You can get a basic supply that will at least be able to turn on and test any amplifier, but trying to run anything more than 1000w and you'll get into the expensive range very quickly. I've got a nice PC power supply I modified with banana jacks for this kind of thing but even with both it's 12V rails it can't supply more than ~40A which is less than 500w of output power on a good day.

 

[brian84corvette 10+ year member]

i use a pair of small 27amp hour agm batterys together to have 12v and 54amp hours avalable - this is plenty to test most 2 chan amps and head units - if i wish to test any of my larger amps - i attach my car battery charger to the batterys and set on fast charge - wich is a good idea anyways - as it usualy charges in the 14.4 to 15.0 volt range and its nice to keep your batterys maintained on the bench.

 

[Kangaroux 5,000+ posts]

I picked up a couple of these a while back just for shits and honestly it works great. It's no where near as adjustable as nicer bench supplies but it has voltage adjustment (I was running mine at 14.4v but I think it goes all the way up to 16-18v).

At $30 for 30A you are paying for 12w/dollar...not too bad. They don't get hot even if they are running at full capacity and there should be no issues wiring up multiple power supplies in parallel if you need more power. All you need to hook it up is a 3 prong power cord (the thicker the cable the better) and attach the hot/ground/neutral to the PSU.

DC 12V 5A 10A 15A 20A 30A Regulated Transformer Power Supply for LED Strip USA | eBay

 

[Spl4200]

i use a pair of small 27amp hour agm batterys together to have 12v and 54amp hours avalable - this is plenty to test most 2 chan amps and head units - if i wish to test any of my larger amps - i attach my car battery charger to the batterys and set on fast charge - wich is a good idea anyways - as it usualy charges in the 14.4 to 15.0 volt range and its nice to keep your batterys maintained on the bench.

This is what I do also.

 

[bigbswa]

Thanks everyone.

I like the way people make their own test power supplies, very cool.

Any opinions on the pyramid brand 12v power supplies I see all over the web?

 

[bigbswa]

Depends on your definition of "high wattage." You can get a basic supply that will at least be able to turn on and test any amplifier, but trying to run anything more than 1000w and you'll get into the expensive range very quickly. I've got a nice PC power supply I modified with banana jacks for this kind of thing but even with both it's 12V rails it can't supply more than ~40A which is less than 500w of output power on a good day.

Yes, all I want to do is be able power on and test speaker outputs on larger amps. 1000w or less. How many amps are needed in the power supply for something like that? I am not looking to keep the large amps powered up to use on the bench just be able to test for functionality.

Thx for all the help

 

[akillj 10+ year member]

Bench PSU's get expensive real quick. If you want a quick 12v to 'make sure it works' then just get the cheapest computer PSU you can find. Next step up would probably be a server PSU, which can supply in the area of 20-50a (not 100% sure, but way more than standard PC PSU's)

Or you can just get a small group 31 bat and a charger and be able to (temporarily) test big amps. A charger holding 14.4 is great, but after like 5 amps (or whatever it's charging at) is exceeded, it will quickly fall to battery resting voltage. So, it really is temporary.

 

[brian84corvette 10+ year member]

as a super rough idea to guideline with - 100 watts of stereo power needs 10 amps as power. 500 watts of used stereo power = pulls 50 amps

so if you use a 5 amp power supply to test with the most your going to be capable of putting out is 50 watts total.

is why its so much better to have a battery or 2 up on the test bench to use as they store alot more amps capable of being used to test with

 

[bigbswa]

as a super rough idea to guideline with - 100 watts of stereo power needs 10 amps as power. 500 watts of used stereo power = pulls 50 amps so if you use a 5 amp power supply to test with the most your going to be capable of putting out is 50 watts total.

is why its so much better to have a battery or 2 up on the test bench to use as they store alot more amps capable of being used to test with

So I am better off with a regular car battery on the bench with the capability of keeping it charged as needed? And just use a power wire with an inline fuse and a ground wire for larger amp testing. Again I dont want the amp to stay running for extended periods just make sure it powers up and the speaker outputs can be tested.

Thx

 

[akillj 10+ year member]

as a super rough idea to guideline with - 100 watts of stereo power needs 10 amps as power. 500 watts of used stereo power = pulls 50 amps so if you use a 5 amp power supply to test with the most your going to be capable of putting out is 50 watts total.

is why its so much better to have a battery or 2 up on the test bench to use as they store alot more amps capable of being used to test with

You're assuming the source is a mere 10 volts... (10v*10a = 100w)

If you use JUST a charger (No batt) you would get available amperage * charging voltage. Assume it's charging at 14.4v and can supply 5A of power.. 14.4 * 5 = 72w. Using a charger without a battery is pointless imo. What OP should do is just get one very small AGM battery and a simple battery charger. Get battery's AH rating and you can figure out from there how much power you can supply for any given amount of time. (50AH * 12.9 = 645W for one hour, or twice that for half an hour, and so on)

I wouldn't even bother adding the chargers supply, because even if it's charging at 14.4, it won't be able to handle any load. (Say it charges at 5A) After 5A is exceeded, the voltage will quickly fall to battery resting voltage anyway.

 

[brian84corvette 10+ year member]

So I am better off with a regular car battery on the bench with the capability of keeping it charged as needed? And just use a power wire with an inline fuse and a ground wire for larger amp testing. Again I dont want the amp to stay running for extended periods just make sure it powers up and the speaker outputs can be tested.
Thx

yes - a car battery up on the bench - with a float charger attached is a great way to power up and test car stereo items

 

[bigbswa]

You're assuming the source is a mere 10 volts... (10v*10a = 100w)
If you use JUST a charger (No batt) you would get available amperage * charging voltage. Assume it's charging at 14.4v and can supply 5A of power.. 14.4 * 5 = 72w. Using a charger without a battery is pointless imo. What OP should do is just get one very small AGM battery and a simple battery charger. Get battery's AH rating and you can figure out from there how much power you can supply for any given amount of time. (50AH * 12.9 = 645W for one hour, or twice that for half an hour, and so on)

I wouldn't even bother adding the chargers supply, because even if it's charging at 14.4, it won't be able to handle any load. (Say it charges at 5A) After 5A is exceeded, the voltage will quickly fall to battery resting voltage anyway.

How small are you referring too? For the AGM battery?

 

---------- Post added at 08:55 PM ---------- Previous post was at 08:55 PM ----------

 

yes - a car battery up on the bench - with a float charger attached is a great way to power up and test car stereo items

Thank you again

 

[Slo_Ride 5,000+ posts]

yes - a car battery up on the bench - with a float charger attached is a great way to power up and test car stereo items

this works for me

 

[brian84corvette 10+ year member]

Kinetik HC600 (KHC600) 12V High Current Car Audio Power Cell

this will work just fine. keep it charged up and it will be a gem in your collection.