DVCC doesn't seems to work?

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mysik asked Jun 16, '20

DVCC doesn't seems to work?

Hello again.

I'm a bit confused with DVCC function.

I've charged my batteries to 100% today, which triggered BMS to stop further charge, but Multi is not stopping, DVCC setting is enabled, BMS is sending all limits to VenusGX correctly, but it looks like Multi is just ignoring it. My DVCC settings are as below:

Battery is 100% charged, BMS set the charge current limit to 0.0A, but multi is still pushing nearly 1A into the batteries:

My system is VenuxGX (with ESS Assistant) + Multiplus II 48V/3000VA + AC coupled PV + Liion batteries with Batrium BMS (connected to VenusGX via CANBus)

I've also noticed that the same thing is happening when BMS is forcing limited charging mode (battery nearly full, CCL set to 0.5A), the Multi also is not limiting power to the set current:

Is that normal??? Am I missing something? Shouldn't Multi limit the power to the set value or I just misunderstood this function?!

BMS DVCC current limit

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Answer 1 · 2020-06-16T19:24:26Z

Jan Zmrhala answered · Jun 16, 2020 at 07:24 PM

Hi,

try to measure the real current which is going to batteries. The CCGX does not show the real data, just approximate data.

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mysik commented · Jun 16, 2020 at 07:32 PM

I have shunt installed, and VenusGX is showing real data (I've also used clamp meter to double check and it is definitely correct)

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Answer 2 · 2020-06-16T23:01:55Z

Daniël Boekel (Victron Energy Staff) answered · Jun 16, 2020 at 11:01 PM

Hi @Mysik

This is well within the accuracy of the Multi's measuring capability, therefor you should (also) make sure the CVL is not too high.

Please note that in an ESS system, when loads fluctuate, DC current can also fluctuate.

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