Understanding the math of electrical loads

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==Wiring audio amplifiers==
 
==Wiring audio amplifiers==
If wiring a 2 kilowatt (2000 w) stereo amplifier, listen up. First and most important, do not try and wire this any distance or use the vehicle's starting battery. Odyssey [[AGM (absorbed glass mat) batteries|AGM batteries]] are your best bet for monster amplifiers due to their dual personality of being both a deep cycle battery and the highest cranking amp battery per pound of battery weight you can buy. Mount the AGM battery right with the audio amplifier so that your leads are heavy and very short in total length. Now you can run that easy-to-work-with 12 ga wiring from your alternator or starting battery back to the AGM for charging. This is why the above method is the ONLY acceptable method, and yes- it involves math again. Your stereo amp, if in fact is a ''true'' 2000 watt unit, is possibly a Class A amp, so efficiency is about 50%. So, 4000 watts input, again divided by 10 volts (remember the voltage drop under heavy loads) = 400 amps. Do you think 20 feet of 8 ga is going to carry this? Nope.  
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If wiring a 2 kilowatt (2000 w) stereo amplifier, listen up. First and most important, do not try and wire this any distance or use the vehicle's starting battery. Odyssey [http://www.crankshaftcoalition.com/wiki/Auto_battery#Absorbed_Glass_Mat_.28AGM.29_batteries AGM (absorbed glass mat) batteries] are your best bet for monster amplifiers due to their dual personality of being both a deep cycle battery and the highest cranking amp battery per pound of battery weight you can buy. Mount the AGM battery right with the audio amplifier so that your leads are heavy and very short in total length. Now you can run that easy-to-work-with 12 ga wiring from your alternator or starting battery back to the AGM for charging. This is why the above method is the ONLY acceptable method, and yes- it involves math again. Your stereo amp, if in fact is a ''true'' 2000 watt unit, is possibly a Class A amp, so efficiency is about 50%. So, 4000 watts input, again divided by 10 volts (remember the voltage drop under heavy loads) = 400 amps. Do you think 20 feet of 8 ga is going to carry this? Nope.  
  
 
Now, a little 15 lb Odyssey battery will put out 680 amps for 5 seconds. If you want to blast your tunes for more than 5 seconds to be truly obnoxious, don't worry, you can. That current draw is at peak output and that doesn't happen often or for only a few milliseconds at a time. With the engine running and sending 15-20 amps back to the AGM battery, you're good to go.  
 
Now, a little 15 lb Odyssey battery will put out 680 amps for 5 seconds. If you want to blast your tunes for more than 5 seconds to be truly obnoxious, don't worry, you can. That current draw is at peak output and that doesn't happen often or for only a few milliseconds at a time. With the engine running and sending 15-20 amps back to the AGM battery, you're good to go.  

Revision as of 15:15, 20 June 2012

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