Good day everyone.
I have a Victron Multiplus II 48V - 8000VA - 110A, cerbo gx, and 2 batteries of 280 A/h. I want to increase the power of my system by 4-5 kW, and connect solar panels. Is it realistic to do this with Victron Multi RS Solar 48V - 6000VA - 100A - MPPT 450/100? Because with parallel connection, you will probably need Multiplus II 48V - 8000VA - 110A and for example SmartSolar MPPT RS.
No to parrallel connect you need identical hardware and firmware so another
All units in one system must be the same type and firmware version; this includes same size, system voltage, and feature set. The type is indicated by the first four digits of the firmware version number. For details, see the “VE.Bus Firmware Numbering System” section in the VE.Bus Firmware versions explained document.
Specify with your Victron distributor that you will be connecting units in parallel or multi-phase and identical units must be supplied.
@lxonline
From my understanding, he wants to daisy chain them…
Otherwise the price of an additional MP2 8kVA for parallel connection plus an MPPT RS for solar, will be much bigger than a single Multi RS Solar.
@Ihor-l
Sorry for late response… 
In theory, yes, you can.
- Multi RS Solar first, then MP2 after, limiting the AC input current of MP2 to about 20A. So 4500W will be supplied by the Multi RS Solar and the rest will be supplied by MP2 as PowerAssist.
- Use the new and untested yet ability of Multi RS Solar to feed-in and/or to function as PV inverter.