Hi
I wabt to buy 12v 4A dc battery in order to power on 15W 230v ampfiler.
There is DC TO AC converter for car that convert 12v car battery to 150W 230v.
Does this converter will power on my ampfiler properly? There is another way to make the ampfiler portable?
Thanks!

 

These in car inverters are pretty common, they usually digitally construct the sinewave so they can cause some noise when used in some applications but as long as your unit has good input filtering it should work ok.

 

A 12V 4Ah battery contains about 30Wh of useful energy. A 150W converter will be inefficient when delivering only 15W to power your 15W amplifier, likely less than 50%. So you can expect the 4Ah battery to run your amplifier for about 1 hour...