How many amps does my inverter provide

Thanks all, I figured I was good but wanted to be sure. The inverter is only going to be powered by an ignition positive source to power a few phone chargers so I'm not too concerned about draining the battery. But it is good to know about the limitations.

Keep in mind in order for your 12VDC Power Inverter to produce the 120VAC@2.5 AMPS it will want to draw around 25AMPS DC from your 12VDC Battery setup...

This is not measuring for any deficiencies

It takes a lot of 12VDC battery current to operate the Power Inverters...

If you only one 12VDC Battery ON-LINE do not expect it to perform very long powering a 25AMP 12VDC load... To keep from doing internal damage to my batteries internally I will not let the Battery get discharged below its approximate 50% charge state which will around 12.0VDC reading on a DC VOLTMETER... When my batteries get down to this level it takes me around three hours of generator run time to get them back up to their 90% charge rate so I can do this all over again the next day/night run off the batteries.

Roy Ken

You're OK.

I ran the numbers and agree with DrewE.

Yes, 18 gauge is sufficient. The ampacity of the cable is somewhere in the vicinity of 7A, or possibly more depending on the temperature rating and type of the cable.

Your computation of current available is correct. The actual current that flows depends on what you plug into the other end of the cord, just as for a household outlet or battery or any other voltage source.