Originally Posted by rwidman
Nope. There is no way to get alternating current out of a battery. I studied this stuff in school
and made a career out of it. The current can vary from zero to one hundred amps or more but it's still not "alternating current".
If your test equipment
is showing you alternating current you are using it incorrectly.
Um, an inverter's only purpose is to get alternating current out of a battery.
Try it with your quality clamp on RMS AC probe. It will read an AC value and it will probably be correct. If you have a DC setting that should show the DC component only but not the AC. Or if your inverter has a shunt put an oscilloscope on the shunt and see what the current looks like. It will not be constant DC.
Any current that is not steady but varies over time has an AC component by definition. Here is a thought problem; if a current waveform varies and you subtract the DC value what is left? The answer is the AC part. You can have an AC current riding on a DC current. The sum of the 2 is the total current.
Inverters draw a lot of AC current from the batteries thus the RMS current is much higher than the DC average. This is often ignored when computing voltage drop in cables. It's why some (most) inverter installation
guides specify wire much larger than people expect. And why inverter installations overheat the wires in many cases.