Need help figuring out max power I can run

[JuiceTin]

This is all on stock electrical, amp output is (130amps), I can do a big 3 and maybe a second battery
With what I thought to decide your max power, is your amp out (130amps) times running voltage (14v) would be your max power I should use for an amp which is (1820w).
But I've heard people run over that that .
So how do I determine the max power I can run

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[grandam888 10+ year member]

I am out of the car audio world the more my ears age. However, I am very much still a hobbyist in the electrical field. With much of my current focus on solar.

This question has been asked a million times since car audio has been a thing. This question is electrical and is answered by math and logic.

The hunger to cram the largest amplifier you can on to a stock electrical system and start adding batteries and capacitors seems to be the narrative every time. Many bandaid type approaches have historically been deployed.

The guys calculating voltage and amperage based on ohms law have it figured out for the most part.

Adding batteries is merely a measure to supplement power and would be helpful on marginally underpowered electrical system. Adding a 63ah battery, useless solution. 63 amps for one hour will not do much for you.

If your going to build an audio system and operate it correctly, you need instrumentation:Voltage meter in cabin .

You need to calculate your power consumption (amperage) of your system and ADD this on top of your current alternator size. Then you install an alternator close to this capacity. Dipping into your vehicles reserve is not the best path forward for reliability. For your car nor your equipment. On obviously smaller systems this can be tolerated. However, your goal appears to be to put the largest amplifier you can into your stock (electrically speaking) vehicle.

Example, I have a stock 130amp alternator. I want to install a 2000 watt amplifier that is 80% efficient vs power consumption. This efficiency doesn't reduce my wattage output, as others have indicated, it increases amperage draw. 2000 watts ÷14 volts=142 amps (100% efficiency). At 80% efficiency, my amperage draw will be 178 amps to produce 2000 watts at 80% efficiency.

A battery will not fix the issues in this scenario.

You want to aim for a at least a 300 amp alternator or a combination of alternators to achieve this. This is where your power is produced. Yes, if you had an rather large battery bank(meaning large number of batteries), and stored power there for later usage, a battery bank is workable. However, financially makes zero sense and only holds so much power.

This is only one piece of the puzzle. You also need;
*Big three upgrade
*Large wire, preferably copper, of the appropriate size
*Voltage drop calculations
*Proper fusing

I personally wouldn't consider adding a large amplifier to your stock electrical system. Anything over 1000 watts is already consuming over half your alternator output. Properly calculating would only be possible if you were to monitor amperage draw of your vehicle vs the alternator output to see what is actually left over on average.

Create an attainable goal with finances and desirable power in mind then build towards that. Stock alternator aside. Your alternator wasn't placed under the hood and engineered to support much beyond what came in the vehicle.