Info:
I have two MPPTs aboard my boat.
1x SmartSolar Charger MPPT 100/20
1x BlueSolar Charger MPPT 100/50
They are attached to the same point on the positive bus.
Wires from the two MPPTs are same length.
Problem:
On the 100/20 the battery voltage is 0.5 to 1.0 volt lower than on the 100/50.
Aside from checking your DC wiring again, I would recommend getting a Smart Battery Sense (and bluetooth dongle for your BlueSolar).
The two MPPT's connected via Venus over VE.Direct.
So it's sadly not possible to add a Bluetooth dongle to the 100/50.
You can use dvcc and svs function on the venus device to share voltage reading from eg a BMV, or the voltage sense wires of a MultiPlus.
It's already active.
Can it have something to do with that the MPPT 100/20 is connected via VE.Direct USB converter to the Venus?
I had the same problem. I do have a CCGX and a BMV700 so, in the end, the answer to this was to set up DVCC in the CCGX. This was not without its challenges. I had to upgrade the firmware on pretty much everything, including my Easysolar 12/1600/70, which had not been upgraded since new and was still on version xxxx154 of the firmware. I also did not have a MK3-USB adapter (only had the MK2 version) so I had to use the deprecated VEFlash utility to update the firmware of the Easysolar but, after following the Victron documentation and the prompts, all went well.
Once this was done I enabled DVCC in the CCGX as well as selecting "shared voltage sense" and now everything uses the voltage at the BMV700.
