I have a sony Explode head unit. Un amplified. You know just an 89$ replacement stereo that is about 5 years old
It claims 52x4 watts output. and sounds surprisingly good powering two kenwood 6x9s, even though they are underdriven.
At near max volume but below distortion levels, when playing reggae, which is heavy on the bass, I will see abou 9 amps draw. perhaps this is an average, with the bass thumps drawing more juice briefly. This level of volume is obnoxious for anybody within the range of a well thrown baseball.
But for simple listening of Country music at volumes that are not going to cause neighbors 10 yards, or even 100 yards awayto curse you and your ancestors siblings, pets and relatives, I highly doubt you are going to come close to anywhere near the 600 watt rating. I suspect at comfortable volume, you will not be drawing any more than 5 amps at 12.6vDc.
The wattage rating on stereos is marketing, rarely actual consumption, and if it does approximate max consumption, it is the abolsute maximum it is capable of, at max volume and only when driving a deep bass note.
Crack a cold one, bring up some Townes Van Zandt's version of dead flowers, ort Blaze Foley's 'clay pigeons' and don't worry about the Stereo's amp draw unless you are only running one group 24 battery that is 4 years old and never saw a true full charge in any of that lifespan.
Leaving 3 incandescent bulbs on inside likely consumes more battery power.
