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jordanb avatar image
jordanb asked

Can VE.Bus BMS connect to CerboGX?

I have a Multiplus 12/3000/50 and plan to add 3 Victron smart lithium batteries. From what I can tell, that means I need the "VE.Bus BMS" - now, my Multiplus has 2 VE.Bus ports, and my plan is to connect one of them to a CerboGX. The other VE.Bus port is connected to the USB adapter and my computer. (PS. This is on a boat).

My assumption is that I can connect the VE.Bus BMS to the 2nd VE.Bus connector on the CerboGX (the other one will be connected to the Multiplus). Is this right?

The documentation I've seen so far show the VE.Bus BMS connected directly to the Multiplus, but I am hoping I can just connect it to the CerboGX. Thanks.

BMS
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3 Answers
Stefanie (Victron Energy Staff) avatar image
Stefanie (Victron Energy Staff) answered ·

Hi @Jordanb

you cannot connect the VE.Bus BMS to the Cerbo GX.

Cerbo GX connects via VE.Bus to the Multi and the Multi with it's second VE.Bus port to the Ve.Bus BMS with the mains detector in between.

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jordanb avatar image jordanb commented ·

Okay, in that case, can I connect the 2nd VE.Bus connector from the CerboGX to the MK3-USB adapter (to my computer) so I can still run VE.Connect on my computer? Thanks! (Pretty sure the answer is yes - but I just want to be sure).

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Stefanie (Victron Energy Staff) avatar image Stefanie (Victron Energy Staff) ♦♦ jordanb commented ·

I never tried connecting the MK3-USB to the VE.Bus port of the Cerbo GX. The manual for the MK3 clearly states that it should connect to the VE.Bus of the MultiPlus.

Same for what I said above about the connection of the Cerbo GX to the MultiPlus and not to the VE:Bus BMS, although it may work as Paul mentioned below.

VE.Bus systems with Lithium batteries and a VE.Bus BMS

  • Connect the Cerbo GX to the socket labelled ‘MultiPlus/Quattro’, or to one of the Multis/Quattros in the system. Do not connect it to the Remote panel socket on the VE.Bus BMS.

  • Note that it will not be possible to control the On/Off/Charger Only switch. This option is automatically disabled in the Cerbo GX menu when a VE.Bus BMS is used. The only way to control a Multi or Quattro when used with a VE.Bus BMS is to add a Digital Multi Control to the system. Setting the input current limit is possible in systems with a VE.Bus BMS.

  • Combining MultiPlus/Quattro with a VE.Bus BMS and a Digital Multi Control is possible. Simply connect the Digital Multi Control to the RJ-45 socket on the VE.Bus BMS labelled Remote panel.

  • To allow auto-power-down in the Cerbo GX in case of a low battery, make sure the Cerbo GX is powered via the VE.Bus BMS: connect Power in V+ on the Cerbo GX to Load disconnect on the VE.Bus BMS. And connect both negative leads to the negative stub of a common Battery.

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hjohnson avatar image hjohnson commented ·
VE.Bus is just that, a bus, using RS485 serial signalling. It doesn’t really matter where the BMS is plugged in, as the two ports on both the Cerbo and on the Multiplus are wired in parallel.
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Paul B avatar image
Paul B answered ·

Hi @Jordanb just for clarity here

First of all the Multis VE.BUS connection must be connected to the Cerbo's VE.Bus connection.

for the VE.BMS unit you can connect it to the second VE.BUS por on the cerbo

OR the secound VE.BUS port on the Multi.

It is better that you connect it to the Multi but it will work both ways

My own VE.BMS unit is connected directly to my Cerbo


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jordanb avatar image jordanb commented ·

Hi Paul,

Thanks for your reply. I wish I could say it brought me clarity, but I have 2 answers from 2 people who say the opposite. Yes you can, no you can't, WRT connect the VE.Bus BMS to the Cerbo, instead of connecting it to the Multi. I guess I will just have to try it and find out eventually.

My second, related question is about the MK3-USB - if I have to connect the VE.Bus BMS directly to the Multi, and I only have 2 VE.Bus connectors on the Multi, I won't be able to connect the MK3-USB to the Multi. Which is why I wanted to connect the BMS to the Cerbo in the first place.

So, other then waiting till I get the Cerbo - which I dont have yet - can you tell me if I can plug the MK3-USB into the Cerbo and allow my computer (VE.Connect) to access not only the Multiplus, but also the other devices connected to the Cerbo, like MPPT controllers, etc.?? Of course, I get that the Cerbo has bluetooth, so I should be able to connect to the Cerbo using BT and use VE.Connect, on my computer - its just that I already bought the MK3-USB and my BT is busy enough already with mouse, keyboard, earbuds - I like the reliability of always-connected USB (I have a 6 port USB hub under the nav desk)



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Paul B avatar image Paul B jordanb commented ·
when you get the cerbo you wont need the MK3 as you can then remote configure the Multiplus. direct from the VRM (inc fw updates)

however yes MOST times but not always you can connect the MK3 to the cerbo. but for things like Fw updates then it wont work it must be connected directly to the multiplus for that.

so its best to connect it to the inverters VE.BUS ports - YES as per victrons recommendation

also re the VE BMS yes it should be connected directly to the Inverters VE.BUS port, ( I think the main reason is that its directly connected its that its not being connect through other items that could be disconnected and thus also disconnecting the ve.bms.

I myself have never had a issue with it being directly connected to the cerbo

you can always try and if does not work NO harm is done - worse case it just wont work


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JohnC avatar image
JohnC answered ·

Hi @Jordanb

I'm curious as to why you need the MK3 adaptor anyway. You mention "VE.Connect", but I think you mean VEConfigure, which is also available remotely via VRM for settings updates.

For monitoring, the various Cerbo options via ethernet or wifi should satisfy. A pc is great for that.

My own MK3 is stored away, only for use to do firmware updates on the Multi, and only then because I have an old CCGX which can't handle remote Multi updates. And if doing that, I'd pull the other VE.Bus plug anyway.

If no internet I could (sorta) understand. But still curious..


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jordanb avatar image jordanb commented ·

So, I guess I just like doing stuff on my computer and having VE.Connect (not VE.Configure) on my computer a click away makes me happy.

And yes, I know once I have the Cerbo I can do everything I want via the Cerbo/BT or via the GX50 Touch (though I read some things are not accessible via the GX50) - at any rate, really appreciate your answers.

I also like having redundant ways to do things in case something breaks (ie. if the GX50 touch dies) but no, there is no "need" strictly speaking. Just a preference.

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