Charge across 2 6V batteries is 11.78. Is that right?

Oh MEX smart chargers are not for daily charging for long term service. Smart chargers are just to get your car started when you leave the lights or radio on too long. Then the normal charging system takes over.

Rely on that for off grid camping. With a generator for a month. Then test its intelligence with a hydrometer. Power Princess camping is as inauthentic as chocolate flavored puffs cereal. A month's undercharging is enough to permanently encapsulate too many plates with hardened sulfates.

I used to camp months at a time fully cycling the batteries and get 8 years service out of a car jar RV battery. Boondock and count cycles rendered. How many RV batteries get cycled 12 times in 3 years and then float belly up? With a smart charger. My 9 year old Concorde battery last tested at 91% capacity. Time to do a reconditioning charge. My 2 volt cells are going on 23 years. Think I may saved ten or 20 grand?

If smart chargers now have AI to know the state of charge please clue me in :)

The 9200 is not a Fraudulent smart charger. It's a darn good one.
In fact in research I've done over the last 15 years None better.

Though that said. I assume occasionally one goes out the door... defective (Why they have a warranty).

I'm sure glad I retired before the advent of fraudulent smart battery chargers.

Absolute agreement.

What should my 6 volt batteries read, NOT connected to a charge source?

about 6.4 volts
The actual resting voltage, or the voltage a battery will settle at 12-24 hours after being removed from the charger, is closer to 2.1 volts per cell, or about 6.4 volts for a 6v battery, and 12.7 volts for a 12v battery. These numbers assume 100% healthy cells, and may vary a bit lower for older batteries.

I do not see why almost all the responses talk about old batteries???? The OP stated NEW Converter and NEW Batteries. So, when plugged into 120 power, the voltage AT the Batteries should be at least over 12.8 volts usually 12.9 to 13.6 volts. Anything LESS and his system is not working correctly. Doug

OP here. Okay, I finally resolved my issues with the charging and everything looks nominal. The only remaining issue is a low tick, tick, tick noise coming from the area of the converter--one tick every 2 seconds or so. Is that normal? What could it be?

Thanks everybody for your support! I've been a member of this forum for many years and it always amazes me how helpful people here are.

A heavily sulfated battery can show 12.8 volts. The problem? It may have 10% of it's original amp hour capacity. Voltage is only useful when battery is not sulfated. It's a **** poor way to determine battery condition.

Correlate weak sister cell gravity with state of charge voltage. It may be significantly different than above chart. The battery must must must be fully charged before doing that. Charge on shore power until ALL CELLS are gently bubbling. Charge correctly and get 300% added life span. Depending how much you abuse by undercharging.