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Trying to run the math to see if I can add my air ride kit on the stock electrical.

 
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Stock alternator is 70 amp. Charging system should run between 14 -14.5 volts when running. Is that what you're looking for?

 
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I think it is. So I have 70 amps to spare and my computer is taking up 55 watts itself. Any idea what the amp - watt conversion is? Then I have 120 watt 4 channel speaker amp and 325 watt bridged subwoofer amp. So I have to do the math on those and then factor in the math on my air ride and see if it's more than what the alternator puts out.

 
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I don't know what the conversion is off the top of my head. I think you'll be fine with the stock alternator honestly.

You won't be encoding video, competing in an SPL contest, in the dark, when it's cold and rainy, rolling your windows up and down, and bouncing your air ride suspension all at the same time. Unless the suspension pulls mad amperage, I wouldn't worry about it.

 
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I've followed some of your builds and you seem to really know your stuff but I'd really like to know the math on it. I'm going to go ahead and order the last of the install parts though, you made me feel easier about the whole thing. Thanks.

EDIT - I think this is my compressor - http://www.airbagit-store.com/produc....asp&ID=104221

 
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Ok so it's an 18 amp draw. The biggest thing would be wiring it properly. I would run a stereo capacitor (a 1 or 2 Farad should do it) on the power wire if you're worried about it, that way the compressor will discharge the cap, which will recharge slowly (comparatively), placing less stress on your electrical system.

But here's some info that may help. (Taken from Here)

You cannot convert watts to amps, since watts are power and amps are coulombs per second (like converting apples to miles). If you have at least least two of the following three: amps, volts and watts then the missing one can be calculated. Since watts are amps multiplied by volts, there is a simple relationship between them.

However, In some engineering disciplines the volts are more or less fixed, for example in house wiring, automotive wiring, or telephone wiring. In these limited fields they often have charts that relate amps to watts and this has confused people. What these charts should be titled is "conversion of amps to watts at a fixed voltage of 110 volts" or "conversion of watts to amps at 13.8 volts," etc.

The Following Equations can be used to convert beween amps, volts, and watts.

Converting Watts to Amps

The conversion of Watts to Amps is governed by the equation Amps = Watts/Volts

For example 12 watts/12 volts = 1 amp
Converting Amps to Watts

The conversion of Amps to Watts is governed by the equation Watts = Amps x Volts

For example 1 amp * 110 volts = 110 watts

Converting Watts to Volts

The conversion of Watts to Volts is governed by the equation Volts = Watts/Amps

For example 100 watts/10 amps = 10 volts

Converting Volts to Watts

The conversion of Volts to Watts is governed by the equation Watts = Amps x Volts

For example 1.5 amps * 12 volts = 18 watts
Converting Volts to Amps at fixed wattage

The conversion of Volts to Amps is governed by the equations Amps = Watts/Volts

For example 120 watts/110 volts = 1.09 amps

Converting Amps to Volts at fixed wattage

The conversion of Amps to Volts is governed by the equation Volts = Watts/Amps

For Example, 48 watts / 12 Amps = 4 Volts

Explanation

Amps are how many electrons flow past a certain point per second. Volts is a measure of how much force that each electron is under. Think of water in a hose. A gallon a minute (think amps) just dribbles out if it is under low pressure (think voltage). But if you restrict the end of the hose, letting the pressure build up, the water can have more power (like watts), even though it is still only one gallon a minute. In fact the power can grow enormous as the pressure builds, to the point that a water knife can cut a sheet of glass. In the same manner as the voltage is increased a small amount of current can turn into a lot of watts.

 
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Okay, so I know car's voltage and I can find out how many watts the electrical system is drawing. From that I can convert it to amps and see if it is more/less than 70? And I guess I can start with the compressor which already takes up 18 amps.

 
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That sounds about right, but I don't know what kind of draw just stock electronics have to figure in to your equation. If you do find it, please post it up as I want to put in an electric power steering pump and need to do some similar figuring.

 
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not everything will be running at once though. so like a 120w amp doesn't always use 10A of current. it may actually use more than that at peak because that's the output and nothing is 100% efficient. but for approximation, use the RMS wattage instead of peak.