Connecting my REC BMS to a Victron Cerbo


  • The CANBus connection to the Victron BMS is pretty straight forward but there are a couple of things you need to know.  We will update this topic as new issues come to light, and we will add them to this first page, so feel free to leave your questions here. Overview: The REC BMS can form an integral part of a networked Victron Energy System by working together with your inverter, MPPTs and chargers to help avoid hard shutdowns.   Notes:
    1.  CANBus allows several different speed rates from 125K BPS to 1Meg BPS (Bits per second).  The default on the REC is usually 500K while the Victron is 250K.
    A customer was kind enough to do some research and found this, which helped him \"In the REC manual it gives you the settings that you need to configure within the CERBO remote console. One difference I found was to plug into the VE-CAN port on the CERBO rather than the BMS-CAN port and set CAN-1 settings to VE.CAN & CAN-bus BMS (250 kbit/s). You can set this at: Settings/Services\"


  • Any hints on having a REC Q, VE.Can MPPT, and MultiPlus inverter/charger all on the same VE.CAN bus?

  • Your best bet is to add a Victron Venus/Cerbo.  The REC will become your Victron DC Power Source and it makes for a pretty slick solution. https://www.victronenergy.com/panel-systems-remote-monitoring/venus-gx Here are a few snips of what the console and Victron VRM page looks like. Even better, by connecting your MPPT to the Cerbo USB port (or via the VE>Bus on larger models)your REC BMS will control it as well. We are hoping to get out a video of how this all connects by year end.

  • Thanks for the quick reply! I do have a Cerbo GX and just realized that the MultiPlus has VE.bus ports, not VE.Can, so it has to be connected to the Cerbo GX. For fault tolerance, I am hoping that my solar charge controller, a SmartSolar MPPT 150/70 VE.Can, is able to obey the REC BMS\' instructions directly from the CANbus, without the Cerbo GX mediating. Do you know if that is possible? Another question: I read in some places that I must configure the MultiPlus using the PC software and USB dongle, but I was expecting to be able to do any and all configuration via the Cerbo GX\'s UI. Thoughts on that? Thanks again, A.

  • I havent actually tested the MPPT VE.CAN direct but the answer should be yes.  (My test MPPT is a smaller USB version so not possible to verify) And you do not need the MK3 USB to VE.Bus cable to configure your MultiPlus.  You can actually tunnel through your Cerbo using the VRM portal.  Depending on internet speeds it can be quite slow and the MK3 direct is much more robust and faster.

  • Hi Rick, I think this thread is appropriate for my question.  I’m connecting the WS500 to a Cerbo GX with REC-BMS Q and Multiplus 24/3000/70-50.  The WS500 is regulating a Nations 24v/150A alternator but the alternator isn’t putting out the expected current.  My question is how do I get visibility into the WS500?  I have it connected to the Cerbo GX on the VE CAN connection (next to the REC-BMS connection) with the CAT5 cable you folks supplied.  Reading the Wakespeed manual leads me to thing the only visibility into the WS500 is using Putty and connecting over the USB connection.  Can you do that while the unit is powered or only when configuring the charge profile?  Should the WS500 show up in the device list on the Cerbo GX?  Thanks for the help.

  • Hi Peter, A bit of flagrant self promotion here but we originally started this company providing software for the WS500.  We have found it to be very helpful in configuring and fine tuning our test systems,  Here is a link to the product and a page snippet showing some recent integration testing we were doing for REC and Wakespeed.  The $ 25 version works well for most users software purchase link:  https://www.offgridsoftwaresolutions.com/product/ws500-configuration-tool-config-version-life- time-windows-64-bit/ and some video demo links here:    https://www.offgridsoftwaresolutions.com/videos/ You will see on the attached page we are using the REC PC software, the Victron VRM and our WS500 tool all together at the same time, with our config tool performing all the real time graphics and logging. And no, the WS500 is not fully integrated with Victron.  In another thread in this forum there is a link to the Github repo with its current status.      

  • Hi Rick, I am configuring a similar system.  I have a 12V @ 560AH LFP house battery bank.  My goal is to get a REC-Active (12V) BMS to control a WS500, Multiplus II inverter/charger and SmartSolar MPPT MC4 VE.Can controller.  Reading this thread, a Cerbo GX and GX Touch display appears to be a way to integrate the CAN bus, but it is not clear to me how the WS500 is recognized by the Cerbo GX as a charge source and whether all of the devices can be accessed and configured through the Cerbo GX.  (You imply that the WS500 is not fully integrated with VE.CAN)  Can these three charge sources be coordinated through a CAN hub of some kind?  If so, what cables do I purchase for the WS500 and REC BMS connections to that hub?.  Thanks for the help!

  • Hi Salvey, The REC BMS functionally acts as a Master DC source on the CANBus network via the Cerbo, and becomes part of the Victron Ecosystem.  You just need to set a few parameters in your Cerbo to use the REC as your main DC supply.  I have attached a few page snippets showing what the REC BMS looks like in a Victron VRM and Cerbo.  With this setup the REC BMS, as the cell approaches a high voltage condition, will send a CANBus maximum current/voltage setpoint to your MPPT, MultiPlus, and the WS500.  This will work as a high limit function and start to pull back the charging of all smart charging devices attached. The WS500 will actually get the signal directly from the REC BMS, based on the CCN setup parameters of your WS500, so it does not need to be fully compliant with rest of the Victron devices.  You just wont be able to see the WS500 parameters and alarms on your Cerbo yet.  (But it should be available in a future release in the next year or so, I would guess.) What does this all mean?  The premise here is that with an integrated system you can modulate your \"Smart\" charging devices to avoid a hard OV trip.  Even better, it will throttle the output to allow your cells to top balance without nuisance trips.  For instance, lets say you have one cell that hits 100% before the others.  With a conventional system, your overall voltage is still telling your chargers to charge, but the BMS will have to issue a hard OV trip to save that cell.  In a \"Smart\" configuration, the REC BMS throttles back all of your Smart charging controllers, to allow the out of balance cell to top balance and remain within the normal range, while the others slowly top up. You will need a couple of cables to do this. REC BMS to Victron Cerbo:    https://www.offgridsoftwaresolutions.com/product/rec-victron-canbus-cable/ WS500 to Victron Cerbo:    https://www.offgridsoftwaresolutions.com/product/rec-ws500-canbus-cable/ And if you dont have a Victron system and just want to connect your WS500 to your REC BMS directly:    https://www.offgridsoftwaresolutions.com/product/rec-ws500-canbus-cable/ And we plan to release a detailed video showing how it all comes together later this winter, that might help too. Hope this makes a bit of sense.

  • Rick - thanks for your prompt response.  What you have described appears to integrate multiple charge sources with an LFP bank. Questions:
    1.  I prefer not to have three different interfaces for device set-up and monitoring (Wakespeed, REC and Victron).  Can I set up the REC and Wakespeed through the Cerbo GX?  If not, what is required for programming these devices.
    2. Once installed, is cell-level battery status and Wakespeed charging information accessible through the Cerbo GX?  Or do I require separate aps/displays to access Wakespeed and REC info including error codes (i.e. do I have to have REC WiFi module installed to see anything?)
    3. While a CAN-based smart system is ideal, failure modes while at sea are paramount.  If the CAN system fails, do charge sources all turn OFF (WS500)?  Without CAN, is manual charging possible?  Do I have to hard-wire emergency by-pass systems?  I\'m just learning about the REC and Wakespeed products so, if failure modes are described in the documentation, please direct me there.
    4. Specific question regarding REC BMS:  I don\'t like large LFP banks to be constantly charged to max every time the sun rises or engine is started, but prefer them to cycle.  Can the charge hysteresis value be set as high as 1.2V (14.0V - 12.8V)?  For example, once the battery reaches full charge (14.0V) the BMS will not call for charging until the pack is 12.8V?
    Do you distribute - or intend to distribute - either Balmar or Victron products? Thank again for your assistance.

  • One more question:  Is the \"OGSS Demo\" the charge information that I would see from the Wakespeed, on the Cerbo GX Touch display? Thanks.

  • Hi Salvey,  I thought it best to reply inline, so please see my replies in blue.   Rick - thanks for your prompt response.  What you have described appears to integrate multiple charge sources with an LFP bank. That\'s correct, all of your Victron MPPT and chargers are connected through the Cerbo to the VE.Bus network and to the WS500 directly. Questions:
    1.  I prefer not to have three different interfaces for device set-up and monitoring (Wakespeed, REC and Victron).  Can I set up the REC and Wakespeed through the Cerbo GX?  If not, what is required for programming these devices.  The beauty of CANBus is that many manufacturers can share data but the downside is having to use different config tools.  Your Wakespeed can be configured using their android/ios tool for basic setup and we developed a Windows config tool that is more granular and has some diagnostic tools as well, which we include for free when you buy a WS500 from us.  Your REC is configured using a PC tool with a command line type of parameter setup, or via the Wi-Fi module.  Your Victron is a bit more complicated.  You will need to download the Victron Mulitplus config tool and purchase a Mk3 adapter or tunnel through your Cerbo using their VRM gateway.  The Cerbo has a decent web UX and you configure it that way.  It all seems a bit intimidating but we are working on a video that will bring it all together, hopefully in the new couple of months.
    2. Once installed, is cell-level battery status and Wakespeed charging information accessible through the Cerbo GX?  Or do I require separate aps/displays to access Wakespeed and REC info including error codes (i.e. do I have to have REC WiFi module installed to see anything?)  Currently the REC is fully integrated into the Victron ecosystem and its parameters can be displayed and alarmed from within the Victron VRM and Cerbo interface.  My last post has a few examples of what the REC looks like in the Victron VRM and Cerbo.  You can see alarms, and detailed cell info.  The WS500 is not yet a fully integrated device.  The REC communicates directly with it to provide supervisory control but the Cerbo can only see a few standard N2K DC suppy PGNs.  Wakespeed is working with Victron and there is an open Github repo with the current status.  We have it listed in another post.  Just search the form for something like \"victron github\"
    3. While a CAN-based smart system is ideal, failure modes while at sea are paramount.  If the CAN system fails, do charge sources all turn OFF (WS500)?  Without CAN, is manual charging possible?  Do I have to hard-wire emergency by-pass systems?  I\'m just learning about the REC and Wakespeed products so, if failure modes are described in the documentation, please direct me there.  Each one of these devices is a standalone product, much like an SLC (Single Loop Controller) in an industrial process environment.  All of the control is performed locally and it just receives setpoint adjustments and interlocks from the central Supervisory DCS system.  In the event of a comms or device failure, all other devices revert back to standalone control and this is why we have the lockout contactor on the REC as a failsafe device.  If the REC BMS can not override a runaway charge device is will just perform a hard OV trip.  Functionality is simply enhanced by having CANBus communications.
    4. Specific question regarding REC BMS:  I don\'t like large LFP banks to be constantly charged to max every time the sun rises or engine is started, but prefer them to cycle.  Can the charge hysteresis value be set as high as 1.2V (14.0V - 12.8V)?  For example, once the battery reaches full charge (14.0V) the BMS will not call for charging until the pack is 12.8V?  Sure, that is not a problem and there are a couple of ways to accomplish this.  You can set up each charge device with a large hysteresis and/or set up your BMS to override your local controller.  You will need to experiment a bit to see what works best for your system
    5. One more question: Is the \"OGSS Demo\" the charge information that I would see from the Wakespeed, on the Cerbo GX Touch display?  I think I answered this above, but the current answer is \"not yet\".  You will see secondary info, like the amount your battery is being charged by the Wakespeed but not directly from the WS500 yet.  Victron and Wakespeed are still working on this.  Remember, NMEA never envisioned a \"Smart Regulator\" and as such there are no standard N2K PGNs so they need to rely on J1939 and RVA PGNs to share data.
    I think I got them all and hopefully our upcoming video will make it more clear. Cheers, Rick Do you distribute - or intend to distribute - either Balmar or Victron products? Thank again for your assistance.

  • Rick - I purchased a WS500 and REC Active BMS in February,  in this thread, you said:
    1. The beauty of CANBus is that many manufacturers can share data but the downside is having to use different config tools.  Your Wakespeed can be configured using their android/ios tool for basic setup and we developed a Windows config tool that is more granular and has some diagnostic tools as well, which we include for free when you buy a WS500 from us.  
    I\'ve installed the hardware for my system and am about to configure everything.  How do I access the WS500 Config SW?  Thanks.

  • you have a couple of options to configure:
    1. there is a free android application that you can use on your phone and connect to the WS500 USB directly using what is called an OTG cable or adapter there is also an Iphone version but this just creates the config file you will need to upload via PC
    2. using a PC you can use a free command line application called Putty, this is pretty hard core if you are not into command line terminals on a computer
    3. there is an application you can purchase for about $20 from this site that runs on a windows PC that allows you to configure and view parameters on your WS500
    4. there is a box you can buy called OPE Tether that will give you a simple web interface to configure your WS500 from any device over a wireless network which is very cool but the most costly option
    I started off using the android app as I have a Samsung galaxy phone but have recently bit the bullet paid the $20 for the Offgrid energy app which I must say is really good ( I am not affiliated in any way)

  • Quote from Rick-admin on January 9, 2022, 9:33 am
    Hi Salvey, The REC BMS functionally acts as a Master DC source on the CANBus network via the Cerbo, and becomes part of the Victron Ecosystem.  You just need to set a few parameters in your Cerbo to use the REC as your main DC supply.  I have attached a few page snippets showing what the REC BMS looks like in a Victron VRM and Cerbo.  With this setup the REC BMS, as the cell approaches a high voltage condition, will send a CANBus maximum current/voltage setpoint to your MPPT, MultiPlus, and the WS500.  This will work as a high limit function and start to pull back the charging of all smart charging devices attached. The WS500 will actually get the signal directly from the REC BMS, based on the CCN setup parameters of your WS500, so it does not need to be fully compliant with rest of the Victron devices.  You just wont be able to see the WS500 parameters and alarms on your Cerbo yet.  (But it should be available in a future release in the next year or so, I would guess.) What does this all mean?  The premise here is that with an integrated system you can modulate your \"Smart\" charging devices to avoid a hard OV trip.  Even better, it will throttle the output to allow your cells to top balance without nuisance trips.  For instance, lets say you have one cell that hits 100% before the others.  With a conventional system, your overall voltage is still telling your chargers to charge, but the BMS will have to issue a hard OV trip to save that cell.  In a \"Smart\" configuration, the REC BMS throttles back all of your Smart charging controllers, to allow the out of balance cell to top balance and remain within the normal range, while the others slowly top up. You will need a couple of cables to do this. REC BMS to Victron Cerbo:    https://www.offgridsoftwaresolutions.com/product/rec-victron-canbus-cable/ WS500 to Victron Cerbo:    https://www.offgridsoftwaresolutions.com/product/rec-ws500-canbus-cable/ And if you dont have a Victron system and just want to connect your WS500 to your REC BMS directly:    https://www.offgridsoftwaresolutions.com/product/rec-ws500-canbus-cable/ And we plan to release a detailed video showing how it all comes together later this winter, that might help too. Hope this makes a bit of sense.
    Hi Rick, In the sample screenshots you provided, I am observing Multiplus in Absorption state and not in \"Externally Controlled\" by REC-BMS. Is this because you have Cerbo\'s DVCC in OFF?

  • Those were just generic snips I grabbed one day to show what data is displayed.  It is a demo system that we experiment with, so it could have been in any state at the time. The idea was to show the parameters that could be displayed, not their current status, but thanks for bringing it to our attention

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