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herzigwi avatar image
herzigwi asked

Multiplus II 48/5000 stays at "Low Battery" even if battery is back again

Hello,

I have the following system:

- a Victron Multiplus II 48/5000 connected to a

- 48V battery system (16 x LiFePo a 3,2V) with a BMS (JBD) system (via RS485)

- a Victron SmartSolar MPPT 150/45 connected to it.

I also have a Raspberry Pi with Venus OS to control the whole system. It also gets the battery state of charge and voltage from the battery system.

Currently the system is not connected to the grid. It is an island system. The Multiplus II still has the default configuration.

For normal operation with battery between 5% an 100% everything works fine. The MPPT loads the battery and using OUT1 I can charge my EV car. On the VRM portal it shows that the

Problem occurs in the following situation. If I discharge to 0% the battery system stops, the battery system will raises "SerialBattery low voltage" and also "low SOC" which the Venus OS gets.
At this time the Multiplus shows the "LOW POWER" LED and stops inverting.

Up to this everything works a expected. The Multiplus shows "fault" on the VRM portal.

If I now charge the battery using the MPPS Smartsolar, even at 20% and a voltage for example of 52,3 Volts, the multiplus still stays at "Low battery". Only way to reset this is to power off the Multiplus and power it on again.

How can I configure the Multiplus to come back again automatically when voltage is again back and go to normal inverting mode?


Thanks for your help!

Multiplus-II
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3 Answers
Alexandra avatar image
Alexandra answered ·

@herzigwi

Do you have ESS programmed? It may be the dynamic cut offs for each load there.

Or it is the low DC voltage warning on the inverter tab. The DC low voltage restart is on the same tab.

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herzigwi avatar image herzigwi commented ·

No, ESS ist not enabled because it is not a grid system.

Low Power is shown as a LED on the Multiplus Chassis.

>"Or it is the low DC voltage warning on the inverter tab. The DC low voltage restart is on the same tab."

Where can I find a way to control the Multiplus using VictronConnect like you seem to do?

On Victron Connect, I can only see two devices:

- Tab Overview: Cerbo GX which allows to enter the VRM portal

- Tab Devices: only shows SmartSolar MPPT 150/45

For me the only way to control the Multiplus is using

- the Venus OS console

- the VRM portal (only updates and saving configuration

As far as I understand the only way to configure the Multiplus is to use a Windows program using the configuration from the VRM portal oder using a VE-BUS USB interface which I currently have connected to the Raspberry.

Unfortunately I can not see any tabs for Multiplus on VictronConnect. And Windows is not the operating system I commonly use. To bad that there is no Android app to control the multiplus or to do this via Venus OS.

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Alexandra avatar image Alexandra ♦ herzigwi commented ·

@herzigwi

You can unplug the mk3 to usb and use your phone (if it is able) with the victron connect app. You would normally unplug from the GX device anyway.

I program many systems with my phone and an otg cable with the MK3 plugged into the ve bus.

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herzigwi avatar image
herzigwi answered ·

Ok. Thanks.

But what is the configuration to have the Multiplus to restart again automatically if battery comnes back again?

It is even easier to power off the Multiplus than to go to it, unplugging the VE.BUJS USB cable from the Venus OS device, plug this to a smart phone and user the restart tab you have shown.

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Alexandra avatar image Alexandra ♦ commented ·

At this point not possible.


Mk3 or vrm with laptop are your two options.

The setting is the dc restart voltage in the inverter tab in victron connect as mentioned before.

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herzigwi avatar image
herzigwi answered ·

The problem still exists even with V502.

Andy from the OffgridGarage has the same problem: https://www.youtube.com/watch?v=iPv_r74vZDo


Only way to get the error cleared is to turn of the multiplus and turn it on again.


There seems to be a firmware problem with firmware v5.0 and higher. Any way to get back to a lower firmware?

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piomark avatar image piomark commented ·
Any update on this topic?

I'm using ESS with multiplus 2/5000 and pylontech US5000.

I just got Low Battery & Overload alarm while multiplus was in mode 2 (Inverting) (weird, as I was drawing about 4kW at the time), multiplus restarted I switched it to mode 3 (On). And since then it stopped reporting anything in VRM.

When I went to garage I can see Low Battery alarm, although I see I have 49.3V.

The multiplus did not restart as it should!?
According to VEConfigure, Dynamic cut off is set to 46V, and DC input low restart to 48V. What am I missing? Why it is not restarting by itself?




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