the-salmon avatar image

Off-grid Multiplus II + SmartSolar MPPT system monitoring


I'm planning an off-grid installation with four solar panels, a SmartSolar MPPT 100/20 (48V) and a MultiPlus II 48/3000/35-32.

I'm wondering how I could monitor my system and I see (at least) two options:

1) Raspberry py

In this case I'd need to get:

  • UTP cable + MK3-USB interface to connect MP II to the Raspy
  • cable + to USB interface to connect the MPPT to the Raspy

Is that right? Or can I connect the MPPT directly to the MP II? In the latter case I don't need to buy to USB interface

2) MultiPlus-II GX 48/3000/35-32

In this case I'd need to get only:

  • cable from MPPT to MP II GX.

Is that right? As MP II GX has only one port, is there any other way to connect MPPTs to it, in case I will expand my system?

Do I really need MK3-USB interface with MP II GX? What's the purpose of USB port??

Which option do you suggest?

Sorry for the large amount of questions and thanks in advance for helping me to have clear ideas :-)


Multiplus-IIRaspberry Pioffgridmultiplus-ii gx48v battery
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1 Answer
Schalk van der Merwe avatar image
Schalk van der Merwe answered ·

Hi @the_salmon, (Mattheo)

1) I would not use a Pi, use a Venus instead. I used them with ABSOLUTELY no issues, try and stick to Victron equipment as far possible, they are tried and tested to work with each other. Remember the Type-2 cable to your Pylon (if this is the same install as your other post - ) and UTP to the Multi.

There are a few posts here to use a Pi in the forum should you want to go that route, the cables you mentioned should work, I'm not an expert there.

2) Unless you want a big cool screen like the CCGX, this is perfect. Better than the Venus as at least you can see some data on the 2 line screen and since it is integrated on the MPII, less cables. Downside is less ports, but based on your install, it is why Victron built these: plain and simple with integrated remote monitoring.

Other questions:

  • Yes, VE-Direct cable from any MPPT to any GX device.
  • When you want to expand, buy a POWERED USB hub and VE.Direct to USB cable. I think you can go up to 6 of these, will say somewhere in the CCGX manual.
  • Regarding the MK3-USB, used to program the MPII, so you better get one.
  • There is quite a few options on the USB:
    • WiFi range extenders,
    • GPRS/GPS modules,
    • VE.Direct to USB,
    • Bluetooth devices,
    • you can do firmware updates from USB (very safe method as sometime online updates can be interrupted)
    • Sorry if I missed a few other USB uses

Don't mean all of these will make your multi 'better', just wanted to add what USB can be used for :)

My suggestion is: MPII GX, MPPT, VE.Direct from MPPT, plain and simple.

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Thanks a lot @Schalk van der Merwe for helping me so much!

Yes, it is the same installation but with few updates:

  • The MPPT suggested from Victron configurator is 100/20 (48V)
  • After lot of reasoning I decided not to go for Lithium batteries, I am afraid temperature range does not match my installation place (ventilated and dedicated room at 900 meters above sea level) - i.e. yesterday it was snowing :-)

Regarding your answer I'm fine with all you said, I think I'll follow your suggestion!

The only remark is that I don't like to have to buy the MK3-USB interface when potentially the MP II FW update could be performed directly from the USB port. Isn't it?

I think the reason why it's not possible to do that is because the USB port is actually connected to the GX card, not to the MP II...

To configure the Multi GX you can use remote ve config via VRM but for FW updates you need a MK3.

Maybe you can buy a used one and sell it after updating your device.

the-salmon avatar image the-salmon Matthias Lange - DE ♦ ·

Got it. Thanks!

Ok, i see the confusion. No, the USB side of the MK3 plugs into the laptop, the RJ45 side into the MPII. See .

Hope that clears it up.

You will notice the exclamation Victron puts on 'trained' engineers/installers/dealers. My advice is don't buy this cable, let the installer/dealer where you purchase the MPII configure it for you. They can even do it in their workshop.

I do want to advise to build a relationship with the local dealer/installer. Let them use their equipment and more importantly expertise to program the finer details. You can always make adjustments on the more 'user type settings' with VRM and remote console, but the core programming gets done on the MPII with MK3.

If you want recommendation on such companies in your area just post your town, Victron will advice on recommended dealer. Even as an installer, i buy from the distributors that gives me the best advice as I also need assistance on some of the advance programming features on Victron products. Remember, the MPII GX gets used in automation, marine and solar industries, so it is a powerful product. Not like products that 'shall not be named' where if you change program 1 to 'B' and program 2 to 'A' you are set... lol

the-salmon avatar image the-salmon Schalk van der Merwe ·

Hello @Schalk van der Merwe. That's exactly my view: I prefer not to buy the MK3-USB converter and let the distributor in my area apply all the settings for me; I'm already in contact with him.

My comment was related to another aspect, it was more a curiosity let's say: why you need MK3-USB converter to program the MP II GX even if, if I got it correctly, there is already a USB female port on the MP II itself! Do you get what I mean? Thanks!

HI @the_salmon

For the first part of your response, perfect :)

For the second part, I am not 100% sure I follow, but lemme try: since the USB on the GX is not intended for MK3 programming, you can use it for other purposes like I explained above. The link above has a picture showing how the MK3 is connected to the GX.

the-salmon avatar image the-salmon Schalk van der Merwe ·

Thanks @Schalk van der Merwe! My question was more: why the USB on the GX is not intended for MK3 programming? But it is just a curiosity... As I told you I will let my distributor configure the equipment for me.