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thshh avatar image
thshh asked

MPPT 75/15 does not show the right PV voltage

Hello,

got a brandnew MPPT 75/15 and it got the following issue:

Connected to two solar panels in serial i measure 44V on the cables. 75/15 states it gets only 13,30V from PV and for that reason it will not start charging.


MPPT has been connected strictly referring to the manual to a 160Ah Vicron Smart LiFePo. Battery has got 13,28V. Was connected to see if the cell balance is ok.


Why does the charger not measure 44V like my multimeter?

MPPT Controllers
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1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

@thshh assuming that your BMS is allowing the mppt to charge, it sounds like you have a high resistance connection between the mppt and panels.

Why does the charger not measure 44V like my multimeter?

You are only measuring the open circuit voltage of the panel (Voc). You also need to load test the panel, to test the panels short circuit current (Isc). How to test your solar panels. properly.

Follow the warnings.

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