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-   -   Can a car amplifier run off of a 9 volt battery? (

realflow100 23rd January 2013 03:25 PM

Can a car amplifier run off of a 9 volt battery?
Could a 9 volt battery even turn on a small car amplifier? (one that's less than 300 watts)
Or would it have to be 11 volts or higher?

Perry Babin 23rd January 2013 03:35 PM

Some amps may power up with 9v. Chip-amps likely would work normally. Amps with switching power power supplies would have a tougher time. If the amp didn't have a low voltage protection circuit, 9v may not be an issue but starting an amplifier's switching power supply with the very limited current that a 9v battery (guessing that you're referring to a NEDA 1604 type battery) can deliver would be a problem. The voltage would drop significantly as the amp started and would drop significantly as the amp produced output. The current draw from the amp would quickly drain the 9v battery.

Amit_112dB 23rd January 2013 08:38 PM

I am sure those class T chip amps will work
My sony xm1s amp needs 10.5-16 volts to run, the manual says
The output power may also be reduced to 1/2 if you move from 13 volts to 9 volts

EWorkshop1708 23rd January 2013 09:00 PM

How about using 2X 9V batteries (18V) with a 7812 regulator + NPN pass transistor to get regulated 12V?

Frank Berry 23rd January 2013 09:03 PM

A 9 volt battery can't produce enough current to operate that type of amplifier.
You can use two of them and a regulator to get 12 volts but you will not get any more current than a single battery can deliver.

JMFahey 23rd January 2013 09:52 PM


a small car amplifier? (one that's less than 300 watts)
"small" and "300 watts" should not be used in the same phrase.

"small" and "1/2W" , as in an LM386 amp is more likely.

Amit_112dB 23rd January 2013 10:16 PM

300 watts
12Volts * 25 amps
Lm7812 regulator will get very hot trying to convert 18 to 12
its current limit is very low
you can stack up 2-3 dozen of them for 300 watts

realflow100 22nd March 2017 04:40 PM

What about a buck converter with 4 of them in series?
Would that possibly be able to run a digital class D 5v-24v 250W (50W per channel) amplifier at low volumes? like no bass just listening volume? buck down to 5 or 12v?
Full brand new alkaline 9v's not the rechargeable kind

I managed to get a really crappy 1$ 1W chip amp to make some sound off a single coin cell like the type in a computer. it was reasonably loud but pretty distorted unless i played at lower volume.

scottjoplin 22nd March 2017 04:53 PM

So...what happened in the intervening four years?.......Bit slack with the updates!

starkeyg 22nd March 2017 04:54 PM


Wold be a whole lot easier to just buy a small 12 volt battery. They come in all sizes.

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