PD or Iota for my upgrade?

BFL13 wrote:
(it would be more revealling if the amps scale were filled in so we can see amps vs time)

The scale at the left is correct for all 3 graphs. Amps start at 79 amps and drop to about 70 amps in the first 20 minutes, then drops more slowly to 60 amps by the 3 hour mark. Amp hours go pretty linearly up and volts have been multiplied by 10 so the end voltage is on the scale at 145 and corresponds to 14.5.

If the PD were working "properly" it would stay at the same amps for the bulk stage until the battery rising voltage makes the amps start to taper.

I think we're seeing it in voltage limited conditions, not current limited due to the resistance of my cable, the battery resistance and the low limited Boost voltage, which I will measure tonight.

IAW the "constant current" stage is not performing like some other converters and chargers do theirs. eg, Vector portables, Powermax and Paramode converters.

I think the PD is doing exactly what other converters would do with my cables/batteries if they had the same boost voltage and the same 80 amp current limit. If they had a lower current limit - say 60 amps - then I suspect they would perform worse and would be 60A limited for the first 3 hours instead of starting at 80 and dropping to 60 over that period. If they had the same 80A current limit as the PD9280 plus had a higher Boost voltage than the PD, then I'd expect better performance - current limited at 80A for even longer.

This is exactly why I started this thread -I was looking for anyone who might have modified the PD circuit to increase the voltage to 14.8 - matching the Trojan voltage recommendation - by reading the circuits in the patents, tracing the circuits in the PD, then modifying it.

I really don't think the decaying current has anything to do with the PD design beyond its boost voltage limit. Of course, I don't have a lower current PD or other converter to test on my system, so I'll have to make do with tests on what I do have. Still, I'm very happy with the PD performance, so far. I haven't done any tweaking to my system and it's already running above 60 amps for 3 hours, which is why I went with the 80A model. I think I've got a decent chance of getting it to the 80A constant current limit by decreasing my cable resistance or tweaking the voltage circuit at least to get it to the spec voltage (since I know it's low).