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How to connect Victron Smart Battery Sense on Pylontechs?

Hi all

I am currently contemplating of adding a 2nd Victron MPPT to my system. As I am not using a GX in my system (using Axperts as inverters), I am looking to use a Smart Battery Sense to create a VE.Smart Network to synchronise the charging of the 2 MPPTs.

But I now have 2 practical questions, which I hope someone might be able to help with:

  1. I understand that the Smart Battery Sense is supposed to be connected directly to the battery's terminals. But how do I best do that for Pylons - given their non-standard terminals? Or do I connect the Smart Battery Sense to the end of the Pylon connection cable (where it connects to my DC busbar)?
  2. I am currently having 4x Pylons connected via a single Pylon connection cable (120A). As with the 2nd MPPT I might in theory be producing up to 135A, I thought it would be safer to add another Pylon connection cable (even though I don't think that the full 135A would ever be pushed into the Pylons as my load also still needs to be supplied). How would I connect the Smart Battery Sense when using 2 sets of Pylon connection cables?

Thanks in advance for inputs

PylontechSmart Battery SenseVE.Smart Network
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Anyone with ideas?

2 Answers
Paul B avatar image
Paul B answered ·

Connect it to the bus bar as this is the point that you want to measure the voltage thats going to both batteries.

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And I take it that the voltage will be the same everywhere across the bus bar - so connecting a 2nd set of Pylon connections cables will not cause any complications (having 2 Pylons connected via the 1st set and the other 2 Pylons via the 2nd set). Correct?

Jack Peters avatar image
Jack Peters answered ·

The correct way to do this would be to add a GX device to the system. Leave the Axpert inverter connected to the battery RS485 port and connect a GX device such as a Venus GX to the battery CAN port and the two MPPTs.

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Thanks for the idea, Jack

But I've got 2 questions:

  1. I am currently using a software called ICC on a Raspberry Pi to control and monitor my system. It connects to the Pylons for accurate data readings and switches my Axperts based on that data. It also reads data from the Victron MPPT (via VE.Direct to USB cable) to give me a complete picture of my whole system. If I add a GX device to the mix, I would lose the ability to have all data consolidated in a single place (because the MPPT would now be connected to the GX via VE.Direct). Or is it possible to also read out data from the GX via VE.Direct to USB?
  2. What significant benefit would I get from the GX and being able to also connect it to my Pylons? I have manually set the charging parameters in the MPPT and my system is running well without the MPPT and Pylons being able to communicate. What would justify spending about 5x more on a Venus GX than for a Smart Battery Sense?

Pylontech US2000/3000 are a smart battery that actively control the charge sources. They do this by direct communication to compatible inverters and via a GX device for Victron systems.

It sounds like you are bypassing these features to some extent on the Axpert and the Victron MPPTs in order to get the monitoring system to work. It might be best to direct this question to your Pylontech distributor incase there are battery warranty implications.

I don't see any significant benefit in adding a smart battery sense to your system. The voltage/temperature measured will be at the DC bus, not at the batteries. It is also not required to synchronise two MPPTs via VE.Smart Networking.

Thanks Jack

Can you please help me understand a few things:

  1. What exactly do you mean by 'actively control the charge sources '? At the moment, the MPPT changes between Bulk/Absorption/Float charging states based on the values that I have manually set. The Pylon gets to 100% every day and seems to be happy. What additional benefit would I have from comms between the Pylon and the MPPT over my current situation?
  2. You write that a Smart Battery Sense 'is also not required to synchronise two MPPTs via VE.Smart Networking'. I thought that you needed either a Smart Battery Sense or a BMV in the mix and cannot create a VE.Smart Network between just 2 MPPT. Am I wrong?

1. as mentioned above Pylontech US2000/3000 are smart batteries they manage the charging on your victron devices, ie the BMS in the battery tells the mppt through the GX whether to bulk charge or float charge, this prevents the battery from over charging and ensures your system would last the maximum time and you are covered by warranty. It also uses the voltages on the battery and SOC on the battery to control the charge.

2. you can link 2 mppts via VE.Smart networking without any other devices. The VE .smart network connects any VE.Smart devices into one network.
The only benefit you will get from have the BMV without the GX devices is to have a way of checking the SOC and voltage and giving your mppt a more accurate voltage which is how it controls its bulk and absorption & float when not controlled by the pylon in this case.

Thanks dgnevans

Especially on the info on VE.Smart Networking. I had only read what seems to be the original info (no longer online) a couple of months ago, which stated that a BMV/Smart Sense was always required. I now also see in the new documentation that you can link 2 MPPT directly