question

The dashboard you are displaying appears to be from VRM and it isn't controlled by the options set in the Cerbo menus. Those settings will control the look of the local display if you have one or the remote console which you can see through VRM or a web browser on the local network.

The charger controller choice depends on a number of issues: open circuit array voltage at minimum temperature and the power you want to go into your batteries. With a 12 volt battery bank, a 20 amp controller will only charge your batteries with 240 watts so you'd be wasting most of the 760 watts available from your panels. You'll never get 100% of the panel power due to sun angle and other factors but you can certainly get much closer. 760 watts at 12 volts is 63 amps. I'd recommend a charge controller that will produce at least 50 amps into the batteries.

The solar charge controller's maximum voltage input must never be exceeded or the unit will be destroyed. If you hook the 4 panels in parallel, the open circuit voltage will be the same as a single panel. If you hook them in series, the open circuit voltage presented to the controller would be 4 times the open circuit voltage. Note that open circuit voltage goes UP with a decrease in temperature so you need to calculate the open circuit voltage at the minimum temperature you will ever see. Lets say your panel has an open circuit voltage of 24 volts. That's probably at 25 degrees C. So at 0 degrees C. At -18 C (0 F) you'd be at 27 volts per panel. With 2 in series you'd need a controller with more than 55 volts input voltage. With 4 in series, you'd need a 110 volt input.

Victron sells a 100 | 50 controller that would handle up to two panels in series, then another two in parallel with that and net you close to 700 watts of charging current. That controller would also handle all 4 panels in parallel but with a total current from the array of 38 amps. You'd need pretty large wires from the array. 2s2p would cut that current in half.

Thank you kevin for your answer on the charge controller. Much appreciated. I am learning quickly but still trying to grasp everything.

>>>The dashboard you are displaying appears to be from VRM and it isn't controlled by the options set in the Cerbo menus

My bmv 712 monitors both my house batteries and my chassis battery. I want to be able to view both remotely. Currently, I can only see my house batteries. I'll hack at this and see if I can figure it out.

>>>The solar charge controller's maximum voltage input must never be exceeded or the unit will be destroyed.

Agree. I think I'll get a total of 3 x 175W (21.6Voc each) panels that are in series and go with the 100/30 victron charge controller. The 100/30 victron is rated at 440w so I'll be over watts by about 85, which I believe will be fine.

I'm not going to get an inverter at this time. Does this plan sound reasonable to you?

@tommyg so the panel/mppt sizing looks about right. Have a look at the calculator on the Victron web site to make sure. https://www.victronenergy.com/mppt-calculator

For the battery voltage you can remotely access the the 712 over the internet using VictronConnect. When you open VictronConnect select VRM at the top of the screen, click on the Cerbo GX and then select devices.

You can also create a custom widget in VRM that will display the auxiliary voltage.

I hope that helps.