>>SQL<< 10+ year member
CarAudio.com Elite
Ok - you are right you did not offer the OP a battery.I base my opinion on actual experience. I didn't even offer a battery for sale? Now I wouldn't run 3k on an 80 alt but for what the op is trying to do, a big batt in the back would be plenty.
I have read many of your posts, I can tell you are a smart guy.
So please explain how his system would work by just adding a second battery.
Op is wanting to run 2 amps
1) 400 watt
2) 1,00 watt
I will go ahead and say his amps will produce that power at 75% efficiency even though I feel 60% would be a more accurate number.
1,500 watts / 12 volts / .75 = 166.66 amps of current draw.
He has an 80 amp alternator
Using a/c , lights, ignition system draws apx 40 - 50 amps
This leaves 30-40 amps to charge the batteries.
lets say OP is on the highway enjoying his system at 75% volume.
166.66 amps (needed current for 100% volume * .75 = 125 amps of current draw
The system will draw the 30 - 40 amps of power that the alternator has left and then start pulling 85 - 95 amps from the battery.
How long can the OP drive like that?
How long will the batteries last being runs down then charged back up?
Wouldn't a 200 amp alt solve all the OP's issues and not require a $200+ second battery (plus wire and connectors)
Plus unlike a battery, the HO alt would provide 13.5 volts which is better for his electrical?
If somehow I am wrong with this simple math (and over 20 years of experience) please explain it to me.
This board is so full of repeated miss-knowledge that it is beyond sickening.
If your system draws more power than your alternator provides all you are doing is running down your expensive, heavy, and dangerous batteries.
You will need to charge them often and that makes no sense to me.
Just run an alternator capable of producing the amperage you need for your current needs.
Please correct me if I am wrong.