mppt vs pwm

jrnymn7 wrote:
So, Isc will decline even before amps taper? So I should not expect to ever see 16 amps from my two 140w panels, except for maybe the first few minutes of bulk?

Look at the IV curves for those panels for exact numbers, but say Isc is about 8.8a. (You get twice that with two panels) You get that until battery voltage rises into the 13s, then it starts down slowly so by the time your Vbat is 14.8, Isc might be 7.x amps so you get 14.x.

In fact, once you get to 14.0 Vbat after a hard day's slogging on solar, the voltage rises quickly from there, so it doesn't take long to reach the 14.8 so the time factor is not much for when amps slide a bit. from 14 to 14.8v. Not really an issue in real life.

When amps taper due to SOC is totally separate and has to do with the charging rate but it now depends on whether the amps in play can be accepted by that size of bank at up to 14.8v or whether the bank is so small it will taper that amount of amps at some lower voltage. A larger bank will keep the same amps up longer to a higher SOC than a smaller bank at the same amps.