I know the basics of electricity, but not how to calculate this... Say I'm adding an amp in my car that puts out 60 watts into 2 channels; what gauge power wires do I need? I know Wattage = Amps * Volts, but I don't know what current the amp is drawing from the battery. I don't want a thicker gauge than I need, and I'm guessing I don't need 10 gauge or lower for these specs!?...

Can anyone tell me how to calculate or better estimate what I need?
tia.

 

Yeah, there is an equation for calculating it. For what you descibed though, 10 AWh will be fine. If you think you might run a larger amp, or more amps in the future you should step up to 8 AWG or larger.

 

just go ahead and run some 2 gauge welder cable... haha

 

It depends on how long the wire will be and how much you plan on expanding in the future.

My general estimates are: (for 15-20 feet of wire, from battery to trunk mounted amp)

0/2 gauge, over 1000W
4 gauge, over 600W
8 gauge, over 200W
10 gauge for everything else.

Better safe than sorry, you could run 12 gauge at the risk of the wires overheating.

 

yea...don't go with 12 guage. i ran a 12 guage wire for my lightning audio amp (50x2 watts RMS) and it shuts off when a bass note hits. its not delivering enough power through the 12 guage. so i switched to 8 gauge and it made a big difference. i originally used my 12 gauge for my 20x2 watt amp (pretty good for only 30 bucks. ) the BIGGER..the BETTER. its never wrong to go with a bigger wire.. of course don't get a 0/1 guage for a 100x1 amp...it wouldn't be wrong..just stupid. hehe

 

unless your amp is like 50 watts (peak), i wouldnt use anything smaller than 8awg. it carrys a lot better than 10 and it is a lot safer.

 

If you are planning on doing a system in your car eventually, then you will have to upgrade your wires from 10 or 8 awg to 4 awg or 1/0 guage. So just to be safe and save some money in the long run, I would run 4 awg from the start.

Or you could, later on, if you ran 8 awg run another 8 awg right beside it.

But the general rule of thumb is no matter what amp run at least 8 Awg wire.

As per calculations:

60 x 2 equals 120 watts

120watts/12Volts equals 10 Amps

However that amp would draw 10 amps if 100% efficient, no amplifier is 100% efficient. Most amps are 1/3 to 1/2 efficent, so the calculations don't work like they are suppose to for this.






[Modified by CanadaCivicSIR, 9:32 PM 1/19/2002]