I have 2 mppt 75/15. I also have a multiplus with a ve.bus smart dongle. I do not have a servo or any other hub in the system. The smart dongle reads direct battery voltage, the mppt read voltage at the controller output which when charging is about 25 volts higher than the battery.
It would seem to be a logical connection for the smart dongle to feed battery voltage to the mppt controllers. But that does not seem to be the case.
Is it possible to make that connection? Is there any other way for the controllers to read true battery voltage?
I have sort of compensated by raising the target charge voltages to the upper limit of the batteries recommended charge voltage.