Victron SOC+Ignore AC feature question

[LeoKa]

Recently we have enjoyed nice sunny days in the PNW. My solar setup on the top is about 2.1KW total, so it generates nice flow of amps.
My Victron Quattro50-120 has a nice feature called "Ignore AC". This can be set to different parameters, when the shore-power AC should be utilized and when disconnected. It works beautifully and I enjoy the extra current coming down to the house load.
I have two circuits. One for the AC loads and one for the DC loads. Both have LP batteries only. The DC is load is charged only by the solar. The AC load is either inverted from the battery, or shore-power AC, if necessary.
One of the settings for this in the Quattro's configuration is the SOC lowest level, when the AC is reconnected, to help the inverter. I set this up, besides other measures, and it works smoothly. My confusion is, when the set SOC is reached and the AC is active again; the SOC goes up to 100% very fast and the Quattro switches back to battery inverting only in few seconds. Now this is not a bad thing in my book, but I do not understand how is it possible for the SOC to change up so quickly? I know that SOC measuring is tricky and it is mainly just a calculation. So, what use do I have of this SOC number, if it is not a real measurement. Please, explain.
My setup:
AC
LP battery 400Ah, Victron Quattro-II-12/3000/120-2x50 2x120, Orion XS 12V/12V-50A, SmartShunt 300A
DC
LP battery 680Ah, Victron SmartSolar Charger MPPT 100/30 x 6

The Orion XS kicks in at certain voltage and feeds the AC circuit with extra.

 

[SteveK]

I may not have understood the question. I do not have your equipment. Here is how I read it.
Sounds like you have bulk charge activated when AC shore is first plugged in which quickly reaches full charge voltage and the ignore AC is then switching shore off and using DC to invert.

Yes SOC is a moving target, I see that on my setup as well with 2 separate readouts seldom agreeing measuring the same batteries.

 

[LeoKa]

I may not have understood the question. I do not have your equipment. Here is how I read it.
Sounds like you have bulk charge activated when AC shore is first plugged in which quickly reaches full charge voltage and the ignore AC is then switching shore off and using DC to invert.

Yes SOC is a moving target, I see that on my setup as well with 2 separate readouts seldom agreeing measuring the same batteries.

Now that clears it out... Lol
Thanks for sharing. I think you have a good explanation.