PD or Iota for my upgrade?

Salvo wrote:
Have you measured the dc input voltage to the center tap of the push-pull transformer under heavy load? I did a quick calculation and determined you need a minimum 125Vdc to output 14.4V.

No, and I'm only getting about 105-106 volts AC under full load from the limited AC voltage on shore power at the RV.

I thought I'd addressed this possibility of limited AC power earlier. I did a test from the generator power source, which is up to 127 under no load and 125 under load. In that test, I saw only limited additional output, and I thought it was close enough to not be a factor.

However, after last night's test, which did not show the performance improvement I expected, I'm beginning to wonder if I'm power limited. It's a bit confusing, however, as both current and power droop. The drop in current is faster than the increase in battery voltage.

In last night's test, I increased the gain of the current to duty cycle feedback loop and limited the max current. I was conservative on the current limit. The results were quite similar to earlier tests - with a slightly lower starting current. That would be consistent with my conservative reduction of the current limit.

I really need to get the PD open to make measurements when running these tests, but it's in an impossibly inaccessible location with the existing power cables. I need more time, but I'm running into vacation departure soon. This is fun, but not as much fun as vacation. :)

The earlier test was not sufficient and I'd already started to think along the same lines you're suggesting.

Can you summarize your calculations for me?