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tkrohmer avatar image
tkrohmer asked

Can I use DVCC with CCGX, BMV-700 and Multiplus compact?

So I have 2 12V GEL batteries connected in series to a multiplus compact 24V/1600VA/40A. The multiplus reads 16V, so it triggers the low voltage alarm and sends every bit of power to the batteries when they are fully charged. I also have connected a BMV-700 and a CCGX to monitor the situation.

I have tried enabling DVCC so that the BMV shares its reading with the multiplus but I haven'yt been able to make it work.

What are your suggestions?

Is the multiplus dead and needs replacement?

How can I make the DVCC feature to work correctly?


Thanks.

MultiPlus Quattro Inverter ChargerBMV Battery MonitorCCGX Color ControlDVCC
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3 Answers
Mark avatar image
Mark answered ·

What firmware version are you running in the the CCGX, Multiplus, BMV and MPPT if you have one - they must be newer than a certain version for it to work. So update the firmware in all devices to the latest released as a first step.

https://www.victronenergy.com/live/ccgx:start

You also need to restart the Multiplus after enabling DVCC for the changes to take effect.

But regarding your system/setup, you have a HUGE 10v voltage difference - there is some kind of PROBLEM, this is not normal or something that DVCC will fix.

Use a digital multimeter to measure the voltage directly at the Multiplus battery terminals to confirm if your problem is in your wiring (what I suspect) or the actual Multiplus unit (or maybe but more unlikely, the Multiplus voltage reading is the true battery voltage and the BMV is faulty/over-reporting)


screenshot-2019-10-04-08-50-13-1.png (257.2 KiB)
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tkrohmer avatar image tkrohmer commented ·

I checked the firmware of all devices and it's all up to date, the conectoins are all ok and the multimeter shows the same as the BMV. So I conclude that the multiplus is failing to read the correct voltage and acts acording to the voltage read. I was interested in DVCC because I thought that maybe the BMV reading would override the Multiplus' own reading and would charge the batteries with the values reported by the BMV.

I have read the DVCC part in CCGX manual and I can't find anything that tells me that It can't be done, or I am missunderstanding the intended use of the DVCC feature.

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Mark avatar image Mark ♦♦ tkrohmer commented ·

Yes with DVCC and SVS activated the MultiPlus will use the voltage as measured by the BMV.

But for safety reasons, there would be a limit for how much compensation can be provided.

An ~10v voltage difference is definitely outside the 'acceptable' range and the system would detect that something is wrong, so it will not use the BMV voltage, provided via DVCC SVS.

Based upon your voltage measurement at the MultiPlus DC terminals you have a problem with your MultiPlus.

Refer to your dealer or installer and get the unit tested - fix the real fault.

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tkrohmer avatar image tkrohmer Mark ♦♦ commented ·

Thanks for the answer and support. :)

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anthony avatar image
anthony answered ·

@tkrohmer first you have to select the BMV as the soc source so it can share it's soc reading to the CCGX https://www.victronenergy.com/live/ccgx:start#battery_state_of_charge_soc

Also if your batteries are showing 16V and not holding charge as you suggest, it sounds like one or both of them is faulty.

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tkrohmer avatar image tkrohmer commented ·

Thanks for your answer @Anthony.

The BMV shows the correct voltage and i measured with a multimeter and the batteries seem ok and fully charged. The battery monitor in the CCGX is set to BMV.

I still can't get the multiplus to use the BMV readings.


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anthony avatar image anthony tkrohmer commented ·

Have you thoroughly checked the connections from the battery bank to the Multi? Have you measured the DC voltage on the terminals in the Multi?

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tkrohmer avatar image tkrohmer anthony commented ·

Yes, it currently has 26,04V same as measured by the BMV and the multi shows 15,66V.

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

The MultiPlus Compact has a fuse inside, maybe this fuse is blown?!

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