question

volker avatar image
volker asked

Multiplus 2 and the MPPT charger showing ca. 2V more DC Voltage than the pylontech

Hello dear Victron community,

DEr Multiplus 2 and the MPPT charger show about 2V more DC voltage than the Pylontech.

I measured the voltage and found that the Pylontech voltage is physically correct.

This makes the SOC wrong and my relay assist is not working as it should The ESS goes into absobtion at 50% SOC.

I have gone through all the settings but can't find anything wrong.

Here is my system:

MP2 3000/48 CX
Pylontech US 3000C.
MPPT 150/45 3000Wp East/West.
and
the EM24

So I hope to get any hint from this community to solve this problem.

What do you guess? Software Hardware or User related problem. The system was running for 1.5 year. Than I got a new CX electronic board () and the newest updates.
The the problems start to raise with the sun.

with sunny greetings

Volker

Multiplus-IIMPPT SmartSolarPylontech
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3 Answers
d-ferdi avatar image
d-ferdi answered ·

hello,

check your cabel-connections, there can be a problem an you have a resistor which is to hight!


goddby

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nickdb avatar image
nickdb answered ·

Your post isn’t clear. Make sure there is a reasonable load/charge running. Then measure at the battery terminals, the inverter terminals, the MPPT terminals, and at the busbar in the middle.

This should give a better understanding of any loss, something which would increase with load.

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volker avatar image
volker answered ·

Hi,
I checked the cables but the connection is very solid. There is no fuse or diode or any other relevant resistor in the cables.
The SOC is also wrong, but this may be due to the wrong voltage.
The discharge may be correct - but is this normal?

If I think back, there has been a drift of problems over the last six months. Last week I saw the unusual voltage difference.

I think the MP2 is out of order and the settings are OK.

I haven't found anything similar on the web. My dealer thinks the settings are wrong, but I go over them again and again and nothing changes.

The only thing I have is on Pylontech, a 3000c. This will come in the future.

Can I calibrate the voltage of the MP2?

Best Volker
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