daedalus

Hey Everyone,

How much power (wrms) can our stock alternator put out after all the car accessories are powered? How much head room should you leave to power other audio accessories not powered through amps (i.e. cd changers, monitors, dvd navigation, etc.) Do you just need to calculate the total amps being drawn by the all the equipment? What are those equations?

Also, if your current draw is more than the stock alternator can handle what are your options for upgrading? What are the average prices for these upgrades? Are there certain high output alternators people have used in our car? How do deep cycle batteries like the Yellow Top Optima play into this?

Maybe some of this information should be added to the S2k Audio FAQ to help guide individuals in choosing equipment for their audio setups.

Thanks for all your help.

MacGyver

There are no equations, just simple algebra. Add up the total current draw of all equipment and hope it falls below the max output of the alternator. Your only option for upgrades is a larger alternator. If the car is running, the battery only acts as a temporary reservoir, so if you're over the current limit, the car will not continue to run very well once the battery has been drained, not to mention deep cycling even a deep cycle" rated battery is not a wise idea when done often.

daedalus

Thanks Macgyver,

Do you know what the current draw for all the stock accessories is? Also, I'm assuming I should use the maximum current draw numbers in order to give myself a little headroom?

NFRs2000NYC

Ive calculated our cars capabilities....and came up with this....

110A x 40% = 44A

So basically, our car can provide about 44A

This mean however, that you dont have 6 pairs of foglights and 67 neons under the car.

So just to backcalculate....

44A x 3 = 132A

132A x 13.8V = 1821.6W

1821.6W / 2 = 910.8 watts RMS.

So basically, with just the motor running, no ac, etc...the car can produce about 900 real watts.

THis number isnt exact, but clearly you can see that you aint powering 3000wrms out of the stock alternator.

daedalus

Thanks Dave,

That's what I was looking for. I just wanted to make sure that a system pushing 550wrms wasn't going to be overtaxing my alternator. Do you think with this amount of power i will have any problems with the a/c running or with hookng up other audio accessories like a cd changer?

MacGyver

Where do these numbers come from?

NFRs2000NYC

The S2000 has a 110A alternator....and *approximately* 40% of power is made available for all the accessories and leaway that manufacturers provide. The 40% if from crutchfield as well.

Correct me if Im wrong though....

daedalus

Dave, didn't your math teacher ever tell you to show your work!

NFRs2000NYC

What do you mean? I did show my work

daedalus

I know, I was J/K. I am just curious as to what the actual current draw is from all the accessories so I know how much I have to play with for the audio setup. I just don't want my lights going out or my battery dying because I have the stereo going and the a/c on. I'm also curious to know how much headroom I have for other parts later on, like DVD nav or something like that.

Or is it just one of those things where i have to wait and see if it happens and then upgrade accordingly?