I have my Xantrex unit set in grid support mode.
A few quick questions ....

Case 1
My SCC is actively harvesting and pulling in at least 600w.
I have my grid support volts set to 51.2, and my batteries are at 52 volts.
The inverter is now using battery power to augment any sub-panel usage above 600w, correct?

Case 2
My SCC is actively harvesting and pulling in 100w.
I have my grid support volts set to 51.2, and my batteries are at 51 volts.
The inverter is now using AC1 to augment any sub-panel usage above 100w, correct?

Case 3
My SCC has now shut down after a normal day and I am not harvesting.
I have my grid support volts set to 51.2, and my batteries are at 51 volts.
The inverter is now using AC1 to augment any sub-panel usage?

Thank you for your assistance. I am still getting used to my new system.

David

Essentially correct, but you need to raise the grid support voltage or else you'll harm your batteries.

It takes a bit of experimentation to get the correct grid support voltage. The best starting point is approximately the manufacturer's recommended "Float" voltage. You'll have to monitor the system's performance over a few clear sunny days, paying careful attention to how early in the day the voltage rises back to the grid support voltage. A few times disconnecting the AC input circuit breaker to verify that the batteries are maintaining capacity is also helping.

If the batteries immediately rise to the grid support voltage, lower it by a single step, then see how the system behaves the next time. As soon as it takes a little longer than before to reach the grid support voltage, increase the value by .1 volts.

What you're doing is minimizing the amount of power that's wasted on keeping the batteries charged, while maximizing the available capacity.

Thanks. I'll give it a whirl.

Now a while later ....

I now have the following set:
Grid Support at 52.8
MPPT Recharge at 52.2
6048 Recharge at 49.9 (Just as a backup to recharge after an outage)

The only oddity I see now is that when I am getting full power from my array (700w +) my Bogart/Trimetric meter is showing the amps level fluctuating quite a bit on a 20 second or so inverval at times. It will sometimes cycle from a varying level of neg 3-7 amps to pos 3-7 amps. As near as I can tell, the MPPT charger is staying in bulk charge mode, pv voltage, pv watts, and system load are all constant at the time this happens. (Battery bank is also in a fully charged state)

I have Concorde sunXtender batteries and the float is supposed to be 52.8-53.5v.

At lower sell power levels and the current firmware the XW-6048 will ramp-up and down the sell wattage, the net is the same as if it was a constant rate. There should be new firm for the XW to minimize the will sell hunting, not sure exactly when it will be released

Thanks. It makes sense now.