kenzo avatar image
kenzo asked

MultiPlus-II stuck with old max charge current setting

Max charge current is set depending on a variety of factors using NodeRed, and has been working flawlessly for months. I recently noticed that it stopped fluctuating as expected, and checked the code to see if it was still set correctly, as well as whether or not it made it into the "remote console" (in DVCC -> "Maximum charge current"). I also checked that there was no interference from the BMS, and that the current voltage wasn't close to any of the limits either.

When disabling the NodeRed code and setting the charge current manually in remote console, this didn't have an effect either.

Ultimately, since I couldn't make sense of the situation and none of the data I reviewed gave any explanation, I decided to restart the VE.Bus system which - as expected - returned things to normal.

The MPs are running firmware 498, I checked the changelog and it doesn't seem that there have been any changes pointing to what I'm describing above (except maybe for "miscellaneous changes"). Is anyone aware of a firmware change that would fix the issue I have described?

Multiplus-IINode-REDDVCCcharge current limit
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2 Answers
gnissah avatar image
gnissah answered ·

I am experiencing the same.

MP on firmware 500. Cerbo on 3.0-beta-42

I limit the max charge current during times of above average E-prices so I can export more PV power. When the price falls below average again, I set the max charge current back to the normal value via modbus.

Although everything (checked on cerbo interface and with dbus-spy) seems OK, still my battery is not charging.

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kenzo avatar image
kenzo answered ·

I am certain this is a bug, or I have been using Node Red wrong. I have been setting "DVCC max charge current" with a simple function that checks SOC, and adjusts the charge current accordingly. Initially I thought I didn't have to care about writing the same value again and again, but that has changed now.

I added a filter after my function that will only forward the payload if it has actually changed, and not blindly send a value all the time. My theory is that re-setting the value (even to the same numeric value) will eventually lead to that value getting stuck in the MP for whatever reason. To test that, I disabled my Node Red function and manually set the max charge current in the remote console which no longer has any effect when the MP gets stuck.

I can also confirm that after a reset of the VE-Bus system, the behavior returns to normal (I can then go back and set max charge current, and can see that the system respects my change and actually does increase the current).

Since this appears like a bug to me, what's the process of getting this to Victron? Do I need to report this to my distributor separately or will someone pick it up from here?

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