Again, The ONLY way voltage can rise very quickly to the setpoint, is at a very high charge rate. Last night, I converter charged my bank, beginning at 85% soc. Voltage started out at 13.08v, and rose from there.... that was at 45a. At 30a, it would take less voltage, over time, to maintain those lower amps. And at a lower starting soc, when charge acceptance is better, even less voltage.
390w / 13.08v = 29.8a
I have seen 18a out of 280w, using pwm, with fairly warm panels. 390 / 280 = 1.39 x 18a = 25a. A warmer panel would produce more amps, nearing the controllers limit. If one chooses to max out their pwm controller, that's their choice.
With mppt, those 390w could easily exceed the 30a limit, with cool panels. 390w plus say 5% = 409.5w / 13.1v = 31.26a. (I see 7% over power rating on fairly warm panels).
