Couple of questions about alternator.How to figure amperage from wattage.Is this corr

[spnkysprky 10+ year member]

Ok,I have a couple of questions.Ok,Im a High voltage Electrician and In my line of work one way to find amperage (when giving at least 2 factors of the equation)is dividing the Total wattage by the volts...So I assume its the same in DC voltage....Then given these factors in my vehicle.I have a total of 1500watts im using(maybe less,Im doing worst scenario).Dividing that with 14.4Volts gives me a total of 104.2AMPS.

Is this the correct way to figure the amperage?I was guessing I could use a 160amp alt???yes or no

If so.....then will my factory (Dodge truck)136amp alternator be enough (I have the basic truck with no extras)to Supply my needs So long as I upgrade the big 3(wire size,Deep cycle battery maybe caps)....are there other factors I should be aware of?

I was thinking not all electrical systems would be exactly 14.4 volts...closer to 13.8 or less so I was thinking to use 12.6 volts instead.My 1 amp is 63% efficient total 995watts RMS and I will add another at 500rms approximate same efficiency.

Im putting it here in this section for better response.

This is their Take...look at MDC http://answers.yahoo.com/question/index;_ylt=AsINmeX5NFQ.wUhUVTUF2fzsy6IX;_ylv=3?qid=20080110211714AAdr8Cv

Click to read more...

 

[spnkysprky 10+ year member]

bump

 

[ngsm13 5,000+ posts]

He is correct.

That is the literal, numerical answer.

Though, that is at 100% full power all the time. Music is dynamic, therefore most of the time the amplifier will not be supplying full power to your speakers.

Not to mention, impedance changes as well... therefore yet another reason the amplifier will not be supplying full power 24/7.

You'll more than likely be okay with your stock alternator, big3, a deep cycle under the hood, and appropriate power/grounds.

If you notice extreme power drains, or it seems to be causing stress then upgrade your alternator. If you have the money, and think it is a good investment, then by all means upgrade your alternator now.

nG