Is this correct or no?

[dirtbagz89 10+ year member]

I found this companies website that sells amps...they explain how to determine if your vehicle's alternator can provide adequate current to the amp.

http://www.quantumaudio.net/amperage.htm

Now using what they say my setup would be like this:

2008 Pontiac G5 stock alternator = 105 amps

105 divided by .40 = 42 amps available

Amp current demands:

Keep in mind I am looking into buying 2 Dual 4 ohm 12" Alpine Type R subs... both are 500 RMS for a total of 1000 RMS.

Now I have a couple amps I'm looking at...my budget is about $200

http://www.sonicelectronix.com/item_11795_Kenwood+KAC-9104D.html

900 watts wired at 1 or 2 ohms...so 900 rms divided by 1800 peak is .50 (50%)

Fuse value on amp = 30a x2 = 60a

60a x .50 = 30 amps

http://www.sonicelectronix.com/item_8177_Kole+Audio+KX1-2000D.html

900 watts wired at 2 ohms...so 900 rms divided by 2000 peak is .45 (45%)

Fuse value on amp = 30a x2 = 60a

60a x .45 = 27 amps

http://www.sonicelectronix.com/item_8403_Kole+Audio+KX1-3000D.html

900 watts wired at 4 ohms...so 900 rms divided by 3000 peak is .3 (30%)

Fuse value on amp = 30a x3 = 90a

90a x .30 = 27 amps

So is this website correct or no? So I would be alright buying these amps using my stock alternator?

Click to read more...

 

[Fiercetimbo17 10+ year member]

ive been running 1600w rms on my stock 90amp alt with a stock battery, only slight dimming under full load

 

[dirtbagz89 10+ year member]

I see...hmmm. I should be pretty good then.

 

[Fusion_FREAK 10+ year member]

I get the basic info, but I don't see how, say a 600rms amp, with a fuse rating of 60 amps only has a 30 amp or so continuous current draw.

I was two amps, with a combined fuse rating of 100 amps, roughly 1000 rms, with a stock ~65 amp alternator. The 6th gen Civics, and some newer models had a tiny *** battery. My CCa rating on my battery is 425A or so. I was getting head light dim, then I did the Big 3, but not my alt to battery wire, because it's a b1tch to get to my alt. I then upgraded to HID headlights, and lost the headlight dim, but the interior and gauge lights would sometimes dim a little on hard notes, but my voltage never went below about 12.5 volts at idle.

I think you'll be fine. Do the Big 3, and get a bigger upfront battery with a high CCA rating.

 

[Fiercetimbo17 10+ year member]

it really just depends on the car, the application, theres way too many factors to just say this will work or will not, just try it out and upgrade as needed

 

[Haunz 10+ year member]

Music has a duty cycle.. even a bass amp that can pull 100amps of current is only going to average 20-30 amps..

A good rule of thumb is divide your alternators output by .33 and that is the maximum amount of current draw your alternator/battery is going to be able to keep up with...

105/.33 = around 300 amps...