Is it safe to have two Battery Monitors, should I remove one?

Question

question

z-zk-z asked Feb 19, '23

Is it safe to have two Battery Monitors, should I remove one?

Hello,

I am using a Victron Smart Shunt (aka Battery Monitor) feeding battery data to other components in my setup (e.g., MPPT charger). Please see my first two setup photos. I recently learned how to have my EG4-LL (version one) batteries to communicate with Cerbo GX (photos aren't showing the communication cables between batteries and Cerbo GX). As you can see from the other photos, I now have two Battery Monitors in my setup. Should I remove the Smart Shunt (it seems the battery communication has more data included, so I should keep that and remove the Smart Shunt)? I also like to know, if it is safe to have two Battery Monitors in my setup. It seems the Smart Shunt is reporting higher SOC value, however the reported charge current and voltage values are similar from both Battery Monitors (see photos, which are captured at different times). Thanks in advance for your reply...

BMS SmartShunt battery VE.Can monitoring

20230215-150414.jpg (3.0 MiB)

20230215-150452.jpg (2.6 MiB)

screenshot-20230219-044423-chrome.jpg (392.4 KiB)

screenshot-20230219-044522-chrome.jpg (386.1 KiB)

screenshot-20230219-044609-chrome.jpg (419.7 KiB)

screenshot-20230219-045001-chrome.jpg (327.6 KiB)

screenshot-20230219-045249-chrome.jpg (387.8 KiB)

screenshot-20230219-045545-chrome.jpg (410.3 KiB)

screenshot-20230219-101200-chrome.jpg (442.8 KiB)

screenshot-20230219-101255-chrome.jpg (357.5 KiB)

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2023-02-20T04:24:22Z

JohnC answered · Feb 20, 2023 at 04:24 AM

Hi @z_zk_z

Victron don't recommend their installers provide more than one SOC reading source, as clients get confused with a second, resulting in complaints and uncertainty. There's likely no real issue with your system because you're aware of it.

That's of course providing your network data is using the correct source. If you're using DVCC (whether deliberately or Forced on by the battery connection), it would be prudent to check what's selected there to provide the master reference data (all types) for the whole system.

Having 2x could also foul your summaries, VRM, etc. If you're happy with how the batt link is working, maybe you could repurpose the shunt more usefully as a dc load monitor or something. They can be reallocated and set to other duties as you choose.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 2 · 2023-02-20T20:53:16Z

Thanks for your reply. DVCC is disabled (I don't even know what that is), anyway I found out that Victron software allows a user to select specific Battery Monitor (see photo below). The menu is located under Settings, System Setup, Battery Monitor. I used to have the Automatic option and I then selected the EG4-LL on CAN bus option. I started getting tons of warnings when the batteries got to 100% SOC which were cleared after a few seconds, so I decided to go back and using the SmartShunt as my Battery Monitor, regardless of the face that everything seemed to work fine. I am still getting those warnings with SmartShunt as my Battery Monitor. I guess, I could disconnect the cable for the EG4-LL CAN BUS (batt link).

Triggered by	Description	Started at	Cleared after
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:22:21	3s
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:22:03	3s
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:21:48	2s
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:21:37	3s
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:21:24	3s
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:21:09	2s
Battery Monitor [512]	Automatic monitoring	High voltage alarm: Warning	2023-02-20 15:20:56	3s

question