My boat has 8 smart solar MPPTs networked together by bluetooth, and 3 IP-43 chargers also networked together. We have a 3kVA Phoenix.
We are installing a new Cerbo GX. Can I run a single VE.Direct cable from one of the MPPTs to the Cerbo, and have the rest of the MPPTs communicate b y bluetooth? Or, does each MPPT need to be connected to a USB hub, and then to the Cerbo? Does it matter which type of USB I use?
Does this also apply to the IP-43s?
To the cerbo through other mppts on ve direct? No. They don’t do that.
If you want them all on the cerbo you have to ve direct or can connect them depending on your models of course.
the quality of the hub will matter. And probably use a powered one.
8+3 that is alot of ve direct 
We have 920 Ah of LFP battery, so 3 IP-43 chargers is still below the recommended charging capacity of 0.2C. These chargers seemed to be the best compromise.
OK, so you’re saying that the 7 slave MPPTs will not communicate by bluetooth with the master MPPT when only the master is connected to the Cerbo by the VE.Direct cable? All the MPPTs need to be physically connected to USB hub?
We have 1200 W of PV panels, and each panel has its own MPPT. We did this to maximize the power we get from the array allowing for shading due to the mast and sails, while avoiding the power loss from blocking diodes. For a PV array, a 0.6 V drop across a diode is a lot of power.
That’s the thought process we used with our limited understanding. It may not be the best way, but it has proven to work well. I spent a lot of time looking at paralleling some panels. Some pairings would have exceeded the 50V limit when using panels that are not UL certified. I know that’s just a BS code “safety” thing.
Correct.
Your set up makes perfect sense with the panel mppt set up. I don’t disagree there.
I do ee that the comms to the cerbo will be interesting to lay out neatly but it is do able.
Lots of $30 cables. Not good. And powered USB-C hubs daisy-chained to the Cerbo, I suppose. Going to take a while for me to figure all this out.
Thanks very much for the help.
Why use a powered hub?
Some of the other type can’t handle the power needed for all the usbs. There are plenty of posts here on the forum about issues with them. Some not cheap not powered ones work well. It usually comes down to cost.
You should be able to use a few ve direct to ve direct cables {3} and the rest on usb to ve direct.
[Unless you have a long distance to run?]
Less than 5 m.
Here’s an example of a hub. I don’t see anyone with all USB-C, and I guess that is not really required for this.
No need for usb C. I have not hear of or used the one you have linked so can’t offer a useful opinion.
There are a few considerations
It is same principle as raspberry pi application. The cerbos are prone to the same issues a Pi has