Amplifier current draw

[KREGER]

Would this be a reasonable answer to the original question?
Amps Draw = Watts/14 Volts??
2000Watts /14Volts = 142.86 Amps of current.
Take the Apms and divide the AMP hours on the specific battery to get an estimate of how long it would take to drain a battery?

[HitIt]

Well, sort of. First off, I am assuming that since you are talking about the battery draining, the boat is not running and the alternator is not charging the battery. The voltage fo the battery will be lower than 14V, especially towards the end of the battery's charge. Second, a 2000W system will only draw 2000W in very short bursts (like when the bass hits). What you are looking for is not the peak (2000W) draw but the average draw. That can be a little hard to figure and depends on the volume of the music and type of music you are listening to. Also, a 2000W system will draw more than 2000/14 amps since the amps are not 100% efficient. That is why they get hot.
You did get all of the math right though
P=I*V (Power = Current * Voltage)
and
Battery capacity (in amp-hours) = current draw (in amps) * time (in hours)

[thmper321]

Good Points. Music current is definitely different from sine wave current which is used to measure the continuous current of an amp.
Also the comment about the amps not being 100% is also correct. I remember watching the techs at Audiobahn measuring an amplifiers output with a current clamp over the power wire while running a sine wave through it and saying the amp make the power it was spec'd at. My comment was yes but how much is being used to heat the amp? :idea: