Precision Power DCX 500.1 - Manual (Page 11)

You should also check the condition and current capacity of the
stock battery negative cable and connections, and replace or
upgrade as necessary. Keep in mind that your amplifiers simply
convert electrical energy to acoustical energy, and any electrical
deficiency will compromise the performance of your sound system.
For more information about charging system upgrades, see you
local authorized
PrecisionPower TM Dealer or call PrecisionPower TM
Technical Support at 1-800-62POWER x2033 .
CURRENT DRAW
The following is a basic formula to be used as a guide to determine
current draw. Your new
DCX amplifier is more efficient than most
other amplifiers. This formula is to be used as a guideline. Using wire
of a larger gauge can only improve the current transfer of your
system. Do NOT use smaller wire gauge.
Total RMS output X 1.5 = Total Input Wattage
Total Input Wattage = Current Draw (in Amps)
Supply Voltage
Example: A DCX amplifier has two channels at 125 watts per
channel RMS rating into 4 ohms (125X2 = 250 watts).
You would use the formula in the following way:
500 W X 1.5 = 750 watts
750W = 62.5 Amps total current draw
12V
10