Good evening, I have a simple question. I recently upgraded my old charge controller, which had a “LOAD” output — I used to connect my inverter there, and it worked fine for very small loads (max 100W).
Now that I’ve bought the Victron 100/30 MPPT, I see that it doesn’t have a “LOAD” output.
My problem is that, given how the wiring is set up in my camper van, I can’t run another cable from the battery (for the inverter) without drilling through the chassis — and I don’t want to make holes. Essentially, there’s just one cable coming directly from the battery, which I somehow need to split: one part going to the charge controller and the other to the inverter, without risking damage to either device.
How can this be done safely, without connecting the Victron inverter directly to the “Battery” terminals (which I assume isn’t correct!)?
graph TD
A[MPPT]
C[Inverter]
BP[(Positive Bus Bar)]
BN[(Negative Bus Bar)]
subgraph E[Battery Compartment]
D[Battery Bank]
end
A -->|Positive| BP
A -->|Negative| BN
C -->|Positive| BP
C -->|Negative| BN
D -->|Positive| BP
D -->|Negative| BN
thanks for the fast reply, i start to understand the need of busbars (in my mind i was thinking of a splitter but i guess this is the same) . Based on your example should it be 2 busbars with 3 poles each? (cause you say 2 pole..) And i just connect them together, that simple? (there is already a 30A fuse on this cable coming from the battery) . System is low wattage (250W inverter /200W PV)
If you can get three pole. Go for it. It was something off the top of my head. Sometimes space can be tight too.
You aren’t using huge amps so one or two lugs stacked wont be a huge deal on the two pole as long as they sit flat and have good contact area
graph TD
A[MPPT]
C[Inverter]
BP[Positive Bus Bar]
BN[Negative Bus Bar]
subgraph E[Battery Compartment]
D[(Battery Bank)]
F[30A Fuse]
end
%% Connections
A -->|Positive| BP
A -->|Negative| BN
C -->|Positive| BP
C -->|Negative| BN
D -->|Positive| F --> BP
D -->|Negative| BN
thanks so much, so if i understand correctly, even with the 2 pole bus bar it should be simple like this? (or if i buy 3 pole busbars then each connection would be seperate)
Hi Owen , can you explain a little bit more about this setup? Based on my low amperage system i might not need but i would like to know about your connection based on my example (1 cable from battery →inverter,charger,extra 12V for led lights etc)
Thank you very much Owen. Basically, you are telling me to also add fuses on the positive busbar for the two outputs going to the inverter’s positive terminal, and the same for the charge controller.
Let me ask you: why do you recommend that specific mega fuse (by the way, I still don’t understand your screenshot) instead of a classic 20A fuse holder? (I have a very small load).
For example, does it fit better onto the existing positive busbar’s M6 studs, or is it because you have a much larger load? I’m asking also for cost reasons, since I already have some fuse holders and i can use both
You can also use an ANL fuse. They dont get hot. The small 6mm midi fuse gets too hot to touch around 30A. The 8mm mega and ANL fuse are good up to 100A before they get hot.
You need a fuse to protect the cable from the battery to the bus. Which you have already.
You need one from the bus to the controller to protect that cable.
Then another from the bus to the inverter to protect that cable.
If you are talking about a classis 20A fuse holder like a blade fuse. They get extremly hot and will melt. They are only good up to 15A with a constant load.
Can you please tell me if this setup diagram including the AML fuses will be ok? (edit: i think those AML should go after the busbar holders for both .. like your example “I would do this with 2 extra single poles …”)
Looks good. Not sure you will get ANL fuses as low as 30 and 40 amps though. {Scratch that, maybe not from Victron but there are other sources}. You will definitely in the mega fuses though.
I put together a super compact fused bus with 2 midi fuse holders, and I used a 200A fuse to connect them. You could also replace it with a copper bus. This is pretty compact and cheap. You would want the MPPT on the left, not going through the 200A fuse and get the best voltage from the battery.
ok now makes even more sense. Can i ask you something else .. the green colour on the possitive connections are also anl or mega fuses? Cause it looks like a Greek P with fuses on both sides 2 green and the 200A fuse on the middle, is this ok?
and connect then something like this diagram:
btw the charge controller is 50Amp and not 30A that i thought but at this moment i will maximum pull 20Amps from the PVs
In the photo I have, they are midi fuses. They are smaller than mega fuses but look similar. You don’t need the + red bus bar; you only need the black (-) connection for all your negative terminals. If you want another positive circuit, add another fuse holder and fuse sized appropriately for the wire.
For your 50A charger, I would use a 60A fuse and 8AWG min - 6AWG prefered wire.
I am running out of gear I have lying around to give you some ideas but you can buy 2 red and one black. If you get a bus with m6 studs you can add midi fuses like this just ignore I have a black and red. This will take any + circuit and you will another black for the - circuit.
Many and different versions for wiring, but with your help I’ve grasped the idea. I’ll make a plan and decide on the best scenario in terms of safety and budget, since in the first phase the system won’t be high demand. Thank you!
