question

Ivar Wagle avatar image

Inverted current values in Multiplus-II

Dear friends,

I am seeing some strange values while charging from grenerator in an offgrid cabin.

System setup:

- REC Q BMS
- 16 Winston Lifepo 300 Ah cells connected in series@48V
- Multiplus-II 48/5000/70-50
- CerboGX (fw. v. 2.73)
- Smart Solar MPPT 250/85
Generator: Honda EU70is

The Multi was installed prevously this year, but were after a while replaced by the dealer with a new unit due to malfunction (constant humming/buzzing sound, even with no load).

Upon installing the replacement, I allso installed a surge protection between the genset and the Multi. The AC-Out L1 leads to a breaker box with overload protection and 4 RDCs. They are all connected to ground. The genset is alsoo tied to ground with another ground ple connected to the chassie.

I am not sur exactely in the installation the fault appeard, but while charging from the genset, the Multiplus AC-In L1 shows negative current (A) and watt (slightly). The AC-Out L1 shows high negative values (-4100W / -18.1A).

However, the BMS menue on the Cerbo shows that the batteries are charging at full power.

On the Pages display the Generator icon shows a slight negative value (around 100W), that the Muti is in bulk mode and that current is flowing into the battery bank. See the attached screen shots.

Can anyone help med make sence of this or sugest where to start the troubleshooting? Preferabliy, suggest a solution?

001-values-from-multiplusjpg.jpg


002-values-from-recbms-charging.jpg


003-pages-showing-negative-production-from-genset.jpg

Multiplus-IIbattery chargingGenerator
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2 Answers
Ivar Wagle avatar image
Ivar Wagle answered ·

In case you are experience the same issue, my excellent dealer, Farco, had the solution within 30 seconds on the phone.

It seems that some devices have an issue with the 3,5mm jack socet on the bottom. The 3,5mm socket is for hooking up the Victron's AC Current Tansofrmer for Multiplus II. On the affected devices, a short-circuit makes the readings charge power flows become inverted. On

The short and sweet solution is to poke an ordinary random 3,5mm plug (your old headset) several times in and out. This apparently bends the springs and contact back to -un-short it.

It immediately fixed the values.

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Rob Duthie avatar image
Rob Duthie answered ·

Hi

Is the Genset AC input transposed?

Need to see all the setting for the Cerbo controller?

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Thank you for replying.

I´m afraid you need to elaborate.

What does it mean that the Genset AC input is transposed?

Thera are alot of settings in the Cerbo. Could you be a litle more specific on the settings we need to expose?

The phase and neutral are swapped over.

Re the Cerbo you need to print out all the set points you can do this via the VRM site

As per sample attached.

Cerbo sample print out.txt

Thanks again, and apologies for late respons.

I have been to find the option of downloading the Cerbo's setpoints on VRM. Have been google it as well. Is it the MultiPlus settings I need to download, eg. download the ve.configure file for the Muti?