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

The use of a hydrometer cuts through the fog and tells you in easy to understand terms yes-or-no, are the batteries getting charged enough to avoid early death. Look at a life cycle chart then moan when your batteries die before they give 10% of the cycle life.

Without knowledge of how to care for a battery expect to replace batteries every few years.

The wizard light will stay steady until the batteries are (nearly) charged. As far as I have been able to work out, it goes to steady, and the corresponding 14.4V output setpoint, when the battery voltage drops below some value, and stays there until it has been at or near the setpoint voltage for a few hours. It then cycles to the lower setpoint voltages and corresponding flashing light signals. The lowest of these does bump the output to the higher voltage for 15 minutes every 24 hours, what they call desulfation mode.

The actual output voltage may be less than the setpoint because of current and power limits, and generally will be when low batteries are receiving a charge.

In short, the converter is behaving as designed, from what you have written.

Read The 12 Volt Side of Life, I found it very helpful.

Batteries are very run down. Let's see you have 220 amp hours (Roughly) and likely need to feed 'em between 100 and 150.. that should take at least 4-6 hours then top 'em off for another 4 hours

I'd say you need to measure voltage out at the terminals on teh PD-9245 as either
1: It is not putting out as it should -or-
2: There is a bad wire/connection or solenoid somewhere -or-
3: You have the batteries DISCONNECTED -or-
4: Circuit breaker of fuse tripped/blown

In the event of an EVEN numbered option your test light is your friend

Starting at the battery
Touch clip to one (Most negative) post tip to the Other (most positive) Light should be dim at that voltage .if it is bright the problem is a bad meter.

Now move clip to ground (Any unpainted metal part which you reasonably expect to be ground) still dim.. Good

Now move out along the positive wire.. IF you find a device test both terminals. if it's 4 terminals the two big ones. DIM DIM not the problem DIM BRIGHT (plugged in) or DIM/Dark (NOT plugged in) Problem found.

But start at the converter It has a pair of 30 amp fuses if Im not mistaken and when replacing they must both be replaced together. UNPLUG FIRST then wait a few for the internal filters to discharge then replace both fuses and plug back in

You can use the test light to check 'em by hookign the clip to the BLACK or negative wire on the converter's 12 volt side and touching the tip to both of the small metal squares in the Windows on the blade fuses. Should both give same result. Different results = blown fuse.

At that level they are considered less than 10 percent charge if I remember my tables correctly. It’s been awhile.

Did you have a load on it when you measured it? Measurements have to be taken at no load.

It doesn't sound right for two NEW batteries.

Batteries are very low. Check the output of the converter, fuses and battery polarity.
You should be 13.2 minimum on the battery when plugged in.

Two full six volts should read 12.7 volts after resting and you need to get them there daily for a long life. Solar is your answer.

It is ok to have the two 6s with slightly different voltages like that.

The batts are quite low and need a recharge ASAP.

I suspect you have been on battery for 12v and the converter is not charging them because of a possible reverse polarity episode that can happen when installing new batteries.