Wiring for adding a second MPPT and two more solar panels

Q&A and troubleshooting
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1

The original install was 4/100watt panels with one 100/50 mppt to a Victron connection block and a 300w Multipllus with 3 100Ah Battle Born Batteries. Second, I added two additional 100 Ah batteries (5 total, now). And now I have now purchased another 100/50 Victron Mppt, and 2 additional solar panels (Rich Solar 250w each). Is there a good diagram for this upgrade.

2 
graph TD
    %% Solar Panels
    subgraph "Solar Array 1 (Original)"
        P1[100W Panel]
        P2[100W Panel]
        P3[100W Panel]
        P4[100W Panel]
    end

    subgraph "Solar Array 2 (New)"
        P5[250W Rich Solar]
        P6[250W Rich Solar]
    end

    %% MPPTs
    MPPT1[Victron 100/50 MPPT #1]
    MPPT2[Victron 100/50 MPPT #2]

    %% Bus Bars
    subgraph "DC Bus Bars"
        BUS_POS[Positive Bus Bar]
        BUS_NEG[Negative Bus Bar]
    end

    %% Battery Bank
    subgraph "Battery Bank (5 × 100Ah Battle Born)"
        B1[100Ah]
        B2[100Ah]
        B3[100Ah]
        B4[100Ah]
        B5[100Ah]
    end

    %% Inverter
    INV[300W Victron Multiplus]

    %% Connections
    P1 --> MPPT1
    P2 --> MPPT1
    P3 --> MPPT1
    P4 --> MPPT1

    P5 --> MPPT2
    P6 --> MPPT2

    MPPT1 --> BUS_POS
    MPPT2 --> BUS_POS
    MPPT1 -.-> BUS_NEG
    MPPT2 -.-> BUS_NEG

    B1 --> BUS_POS
    B2 --> BUS_POS
    B3 --> BUS_POS
    B4 --> BUS_POS
    B5 --> BUS_POS

    B1 -.-> BUS_NEG
    B2 -.-> BUS_NEG
    B3 -.-> BUS_NEG
    B4 -.-> BUS_NEG
    B5 -.-> BUS_NEG

    BUS_POS --> INV
    BUS_NEG --> INV

Obviously you need to have fuses and disconnects in place as well but that is the basic flow.

Are you series connecting the new panels and the old ones? i wasn’t sure so i left them a parallel. But you know what is done there.

You do need pv disconnects tha fusing on the battery side before the bus bar to the mppts and inverter. That information including wiring size can be found in the manual on the product page.

3 
graph TD
    %% Inverter
    INV[300W Victron Multiplus]

    %% Bus Bars
    subgraph "DC Bus Bars"
        BUS_POS[Positive Bus Bar]
        BUS_NEG[Negative Bus Bar]
    end

    %% Battery Bank
    subgraph "Battery Bank (5 × 100Ah Battle Born)"
        B1[100Ah]
        B2[100Ah]
        B3[100Ah]
        B4[100Ah]
        B5[100Ah]
    end

    %% MPPTs
    MPPT1[Victron 100/50 MPPT #1]
    MPPT2[Victron 100/50 MPPT #2]

    %% Solar Panels
    subgraph "Solar Array 1 (Original)"
        P1[100W Panel]
        P2[100W Panel]
        P3[100W Panel]
        P4[100W Panel]
    end

    subgraph "Solar Array 2 (New)"
        P5[250W Rich Solar]
        P6[250W Rich Solar]
    end

    %% Connections
    P1 --> P2
    P2 --> MPPT1
    P3 --> P4
    P4 --> MPPT1
    
    P5 --> P6
    P6 --> MPPT2
    
    MPPT1 --> BUS_POS
    MPPT2 --> BUS_POS
    MPPT1 -.-> BUS_NEG
    MPPT2 -.-> BUS_NEG

    B1 --> BUS_POS
    B2 --> BUS_POS
    B3 --> BUS_POS
    B4 --> BUS_POS
    B5 --> BUS_POS

    B1 -.-> BUS_NEG
    B2 -.-> BUS_NEG
    B3 -.-> BUS_NEG
    B4 -.-> BUS_NEG
    B5 -.-> BUS_NEG

    BUS_POS --> INV
    BUS_NEG -.-> INV