CVL of DVCC does not work

We are operating 5 quite similar victron 3phase systems with ac-out connected pv-inverters and diy lf280k battery packs with serialbattery-driver.

The serialbattery-driver reduces CVL (charge voltage limitation) if a single cell rises above 3.46v to prevent overcharging of this single cell and give time to the active balancer (jkbms).

This works fine for 4 of the 5 systems.

But the 5th systems seem not to obey CVL especially when we have high pv-Power (i don't understand this dependancy - grid is on and the pv-power can be fed into the grid).

I checked all settings and compared them to the other 4 systems that work fine.

The only difference I can see is the way the serialnummer of the multiplus are displayed in the remote console:

Here the system that does not work:

For the other 4 good working systems only the present devices are shown:

Does anyone have an idea?

Every advice is very much appreciated!

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nickdb ♦♦ commented · Apr 23 at 05:35 AM

Same Cerbo versions and firmware?

The serial driver is unsupported, so if the obvious is eliminated then, this is better off moved to modifications section.

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Alexandra ♦ nickdb ♦♦ commented · Apr 23 at 07:10 AM

In commissioning was there any differences noted on the ve bus dc measurements?

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cflenker Alexandra ♦ commented · Apr 23 at 08:26 AM

All DC voltage measurements are quite the same (VE-Bus, SmartShunt, SerialBatteryDriver) and all are far above CVL.

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cflenker nickdb ♦♦ commented · Apr 23 at 08:04 AM

Thank you for moving to the correct chapter.

Cerbo-S GX is on the newest Version V3.30.

On the other systems we use Cerbo GX (without -S) but same Firmware Version V3.30.

May this be the Problem? I think Cerbo-S GS should work as well. Don't you think so?

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nickdb ♦♦ cflenker commented · Apr 23 at 08:11 AM

Identical OS, that won’t contribute.

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Al commented · Apr 23 at 10:11 AM

I guess you only have one BMS for each installation, so you don't need battery aggregator? The Pulquero aggregator needs an edit to the config. JSON to allow serial battery CVL limitation to work as expected.

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cflenker Al commented · Apr 23 at 11:10 AM

Hello @Al, thanks for your hint. In this installation we only use one battery-pack and only one BMS. I can only measure the CVL that comes out of the serialbattery-driver. This CVL is correct. It would be interesting to measure the CVL on the VE.Bus to the Multis. But I don't have an idea how to do this. Is there a way to do this?

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Al cflenker commented · Apr 23 at 11:29 AM

I'm not sure as I've not checked myself when CVL is limiting, but if you look on dbus-spy at your BMS (Serialbattery JKBMS) and Info/MaxChargeVoltage when you hope to see limiting, does it reduce? If it does, is it also the same for the system: Control/EffectiveChargeVoltage? I assume it should pass on the CVL voltage to System.

You could install batteryaggregator then you could see on the remote console the aggregator in device list and parameters tab will show the called for CVL. < but that's maybe a lot of hassle to install everything and set up just to check.

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cflenker Al commented · Apr 23 at 11:43 AM

Thanks @Al, that's a good idea. I will try with MQTT Explorer. I think the dbus is being mappt to MQTT. That's the easiest way for the first step. If that doesn't take me further, i will have to use dbus-spy. But I am not familiar with that yet.

Thanks a lot!

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Al cflenker commented · Apr 23 at 12:06 PM

I'm not familiar with MQTT, but If you have terminal access with putty or similar it's quite easy. just type: dbus-spy in the command line, then use arrow keys to navigate. Ctrl+C to Exit.

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