Just to be incredibly mean and pernickety about a question a good friend has asked in a public place, let me re-state Q1):

1) How much Power does your amplifier consume (Wattage)?
1A) What is your battery Voltage (12V or 24V)?


Using P = VI (Power = Volts X Current) you should be able to work out:

2) What is the curent draw of your amplifier at peak driven watts (RMS)?