OK, here's what I found out, the downloaded manual is worthless. But what I could determine is that charge controller is a PWM style without battery current input/monitoring. So, no shunt.
The battery AHr is based on a battery "capacitance" setting, which you will have to determine and enter yourself. This value would be the manufacturer's published 20 hour rate. The AHr you see is worthless without a shunt to actually measure the current usage both in and out of the battery.
The state of charge (soc) seems to be nothing more than a voltage reading from the battery. This value is calculated as a percentage of full charge volts (13.7) to low volts (10.5). The soc will give you an idea of the battery condition, but is by no means accurate. Case in point..your chasis alternated should be charging at 14.5 volts or so. The coach converter should be charging around. 13.6 or so. Using the manual's specified settings, anything >13.7 would be 100%, just under that would be just under 100%.
Now, for your charge controller.. this CC is a PWM style...basically a fancy switch that turns on when the solar panel voltage is higher than the battery voltage. If your batteries had a low SOC and the solar panel wasn't getting direct bright sun, there wouldn't be enough current made (you said you have an 85 watt panel which is 6.8 amps at perfect conditions) to offset parasitic load. Thus your battery won't actually charge.
Any questions? I hope this is clearer than mud.
2000 Cherokee, LEDs, solar, inverter, etc. '07 Tundra 5.7L DC-LB, modded as well.
2000 Cherokee 29BH with 6V batteries, LED lights & 400 watts of solar power, flipped axles and raised. 2007 Tundra 5.7L DC-LB with lots of mods. C-co, 8/158th AVN Maint.