How big of an alternator do I need for 3000 watts?
3000 watt / 12V is equal to 250A. A 250A alternator is needed to keep up with it. Since your engine would have to work just as hard as any portable 3KW generator to keep up with the amplifier, you would need a large fuel tank. If you want to run this amplifier without the engine running, you need to know how often and how long you want to run it.
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