Two Main Sources of Power in Your System

[MJS_IraggiAlts 0]

I get a lot of PM's with comments that go like this... 

"I'd like to be in the upper 13's or even 14's full tilt",  & hoping for that with one, maybe two alternators  on 12,000 watts of power."

There are two main sources of power in your system. One is the alternator, which is around 14.5 volts, & the other is the battery, which is 12.8-13.3 at best.    So basically two voltage levels, 13.0  & 14.5,... & a very, very small gray area in-between those two numbers. The higher voltage source is the one producing ALL the current until the voltage drops to the next highest source, then that one will start helping. That's why you see voltage go from 14.5 to upper 12's very fast once it starts to move.

If you want "Alternator Voltage", anything higher than very low 13's,..  then you need more alternator power than you are pulling from your amplifiers.
So if you have, let's say,12,000 watts, which is around 1000-1400 amps of current draw, depending on the amplifier & how you have it configured  ...  You'll need 1000-1400 amps, or more, of alternator power to maintain - "Alternator Voltage", (13.5 or higher)

The only real exception to this rule are banks of caps.  Caps produce voltage at the same level you charge them to.  .. so in essence, they act just like an alternator, the only difference being they don't produce their own power, They produce what the alt puts in them.

Thoughts?