Hello dear Victron community,
The Multiplus 2 and the MPPT charger show more than +3V DC voltage difference than the Pylontech. This started from 1V as I remember the first time 2 years ago. But now it is worse and the ESS does not work with this behaviour.
Also the external relais is not switching correctly due to the wrong calculation of the SOC.
I measured the voltage and found that the Pylontech voltage is physically correct.
The difference is when charging or discharging or when idle, so the wiring is OK and no resistance can cause this behaviour.
I've gone through all the settings and can't find anything wrong.
Here is my system:
MP2 3000/48 CX
Pylontech US 3000C.
MPPT 150/100 3000Wp East/West.
and
the EM24
So I am hoping to get any hint from this community to solve this problem.
Is it possible to calibrate the MP2 to the real voltage somehow?
I read in the forum:
"Yes, I have found a solution. The local Victron service centre re-calibrated the Multiplus DC bus voltage to match that of the BMS and a multi-meter. They managed to do this by establishing a remote desktop connection to my laptop which was connected to the Multiplus with an MK3 interface. They ran a software app that allows you to enter a voltage to calibrate the VE Bus card inside the Multiplus."
So can I do a calibration or is the MP2 faulty? It is still under warranty.
with sunny greetings
Volker
