REC Q Series BMS + WS500 + Victron + charge/discharge control

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  Thomas

  5/3/23, 9:16 PM

  I am looking into upgrading my existing van system with a dedicated second alternator.  I have been searching the forum and the REC BMS download site and I find some info on Wakespeed + Victron for the REC Active BMS, but not for the REC Q BMS.

  I also find some info on use of the REC Q BMS optocoupler and internal relay to achieve independent control of charge and discharge, but it seems to require custom firmware and I'm not clear which version or if that custom firmware also supports Victron and Wakespeed.

  For reference, my existing system would migrate as follows:

  • 24V 280Ah LiFePO4 pack (existing BMS to be replaced with REC Q BMS)
  • Victron Cerbo GX
  • Victron Multiplus 24/3000/70 (currently using Two Signal BMS Support--would change to CAN for control)
  • Victron 12/24 DC-DC converter for charging from engine alternator (non-CAN, HW controlled by BMS)
  • Victron MPPT (non-CAN, hardware controlled by BMS)
  • Victron BatteryProtect (for DC loads, HW controlled by BMS)

  I'm looking for documention on hardware, FW version, and configuration that will support all of the following:

  • REC Q BMS
  • Victron including Cerbo GX
  • WS500
  • Independent non-CAN hardware control for 'Allow to charge' and 'Allow to discharge'

  Any pointers to correct documentation would be appreciated.

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  Rick OGM Support Staff

  5/4/23, 6:55 PM

  Happy to help you here.

  First, all REC BMS information is available for download at our REC North America or REC head Office sites

  https://rec-bms-na.com/downloads/

  https://www.rec-bms.com/

  And here is a link to a wiring diagram similar to your configuration:  

  https://rec-bms-na.com/download/32/rec-q-series-bms-sketches/1304/rec-q-series-bms-with-victron-and-ws500-diagram-rec-q-24v-with-precharge_3-2p-8s-1-0-4.pdf  

  Second, for your 24V LFP pack you are correct, you would use the Q Series with the Victron and WS500 drivers.  

  Note that your WS500, Victron MPPT and your Victron Inverter/charger can all be controlled by the REC BMS via CANBus and using the CVCC control algorithm

  In the past if you needed custom configuration it required a firmware swap but last year REC upgraded the controller memory and added functionality to allow for custom if/then/else type control on the unused outputs when used in conjuction  with the "Tasks" page of the Wi-Fi module.  Page screenshot attached for reference.

  The challenge with the Q Series is that you only have one spare output and you are looking for both a mechanical 'Allow to charge' and 'Allow to discharge' outputs as well as the CANBus internal software control.

  For this you will want to look at the new 2Q BMS being released in May-June this year (2023).  It includes a high current output for your main disconnect relay as well as two (2) configurable low current opto outputs.

  Documention is still preliminary but just this week we have released it for pre-order.  Here is the link for reference.

  https://ogm-energy.com/products/rec-si-q-series-16s-bms-2-0

  

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  Thomas

  5/4/23, 8:26 PM

  Thanks, very helpful!  And good news about the 2Q, it sounds like what I need.

  If I understand correctly, I could configure the two opto outputs to have one act as 'Allow to charge' and one as 'Allow to discharge,' while also having a separate main disconnect relay.

  Are all three outputs (two opto and one high current) fully configurable as to which BMS conditions trip each output?

  Is there a preliminary manual available yet?  I looked on the REC website and I only see the existing Q manual.

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• R

  Rick OGM Support Staff

  5/4/23, 9:45 PM

  The high current output is dedicated to the Main trip contactor/relay.  Both opto1 and opto2 are configurable for any available function.

  We are hoping to have first release manuals in a few weeks.  If you are signed up for notices (on the page footer) or go to your account (the little guy on the top right of the site) then click on Profiles, we will be putting out a formal announcement on it.

  If you need assistance building a kit feel free to reach out to us at support@ogm-energy.com

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  Thomas

  5/5/23, 1:32 PM

  Thanks, I signed up for notices and sent a request on building a kit to support. 

  Looking at the Wifi module vs. PC SW.  What is configurable via Cerbo, vs. requiring Wifi or PC SW?  I couldn't find that in the Q manual nor in the PC SW manual.

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• R

  Rick OGM Support Staff

  6/11/23, 11:53 AM

  The Cerbo does not provide battery settings functionality for the BMS.  You can set up alarms, logs and DVCC functionality though

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