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Iain avatar image
Iain asked

Voltage difference between Multiplus II and Pylontech

Morning All.

A system we monitor has a large voltage discrepancy between pylontech readings and Multiplus II 48/.

Pylontech shows 50v

Mulitplus II shows 58v

Settings through Cerbo and VE configure are fine, the installer of the system is experienced. No error codes. Victron firmware all up to date. ESS with grid, loads are modest. I´ve read of small divergence on the forum but not seen any clues to explain such a big difference.

Any suggestions to help me figure this out would be greatfully appreciated.

Thanks

Multiplus-IIPylontechvoltage
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3 Answers
Jason - UK avatar image
Jason - UK answered ·

@Iain Which one is the correct reading? have you tested the voltages yourself both ends? That difference seems really odd.

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Iain avatar image
Iain answered ·

Real reading is the battery voltage. The installer checked both ends. To me it seems to big a difference to be physical. The installer is good and experienced so the basics should be covered (!)

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Jason - UK avatar image Jason - UK commented ·
@Iain The 58v reading, is that coming from the Pylontech batteries communicated to the MPII via comms? Do you have screen shots of where this information is coming from?
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Iain avatar image Iain Jason - UK commented ·

Battery voltage readings from the device list/pylontech. this reading also corresponds to the voltage information available through the MPPT 150/45 that is also on the system. DVCC is forced on of course. The values below carry through to the advanced format...


screenshot-2024-03-08-131841.pngscreenshot-2024-03-08-131841.png

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screenshot-2024-03-08-131841.png (49.6 KiB)
screenshot-2024-03-08-131816.png (42.7 KiB)
proton avatar image
proton answered ·

What does the VRM portal show over 24h for the DC value of the Multiplus ? Or what do you see during night, e.g. MPPT is not loading/not in absorbation?
I assume a incorrect, too high, (for 15 cell Pylontech) default setting on the MPPT - which is 57.6V default during absorbation phase. (from the datasheet).

Cheers


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