question

skillet avatar image
skillet asked

Added a second battery and now displayed values not adding up

Hi All


Client has a Multiplus II 48 | 5000 with a MPPT 250 | 100 with a Cerbo GX. System was installed with a single Dyness 5.12kWh battery and client has added a 2nd one of these batteries now.


Comms to the batteries seems to be fine but monitoring figures does not seem to add up now:


1356W seems to go missing from looking at the below?


Would greatly appreciate assistance

screenshot-2022-11-08-at-180613.png
Multiplus-IIsmart mppt
8 comments
2 |3000

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Alexandra avatar image Alexandra ♦ commented ·
@Skillet

By battery comms are fine, what do you mean?

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skillet avatar image skillet Alexandra ♦ commented ·
Sorry, meaning that it detects both batteries.
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pwfarnell avatar image pwfarnell commented ·

Are you relying on the batteries to report charge current rather than a Victron shunt.

1356W is missing, which is pretty close to the reported 1439W going to the battery, simple thought is the new battery is also charging with approx 1400W but it is not reporting this.

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skillet avatar image skillet pwfarnell commented ·
No shunt yes @pwfarnell.

Does this mean that the shunt is required to report the stats of the 2nd battery?

Should the BMS not be bale to report this back to the system?

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Alexandra avatar image Alexandra ♦ skillet commented ·
@Skillet

If both batteries are present on the GX, they should both be reporting their current.

Would you mind sharing a screenshot of that?

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skillet avatar image skillet Alexandra ♦ commented ·

Hi @Alexandra

The client has invited me to VRM to allow me to check but it seems this information is not available to me as a "Monitoring" user.

Client cannot find the section where he saw both batteries being display previously.


Do I need to go out to site to get this info by connecting to the system directly or is there another way to get this info?

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Alexandra avatar image Alexandra ♦ skillet commented ·

Ah yes. Monitoring only locks you out of alot of features. You will definitely need better acces if they really want your help. So if that is in person that will be the way to do it, unless the person is prepared/able to upgrade your level of access.

The other way is if an admin loads the widgets for the battery monitor, particularly the DCL and CCL one. Are they sure they have the battery dip settings correct? I have found this often missed on set up.


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skillet avatar image skillet Alexandra ♦ commented ·

What I find strange is that the system was installed with the comms cable from the inverter connected to the OUT on the first battery. So when the 2nd battery got installed they connected the IN from this battery to the OUT on the new battery.


I have asked client to connect INV -> BMS-IN -> BMS-OUT -> BMS-IN.


He will give it a shot and come back to me.


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1 Answer
skillet avatar image
skillet answered ·

Hi Guys.


Issue solved. The installers of the system connected the comms cable from inverter to the battery into the OUT port on the battery. No idea how, but this seemed to have worked. With the install of the 2nd battery, the cable got connected to the available IN port on the first battery to the OUT port on the new battery.


Swapped the cables around and now working perfectly. Thanks for all the help!!!

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