question

spangled avatar image
spangled asked

MPPT 75/15 odd voltage drop...!

HI all, have an odd one. PV is sitting at about 19v and 3.5mw, the battery is 12.56. When I connect the PV the voltage drops to 12.48 and does not charge. It's going through the MPPT 75/15.

The Victron app is showing voltage at 12.48 but 0w charging! Could this be a charger unit fault?

100w PV, 2x 125ah leisure batteries.

Thanks

MPPT Controllers
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2 Answers
anthony-d avatar image
anthony-d answered ·

PV open circuit 19V. How are you measuring the 3.5mW?

So the PV array voltage drops to 12.48V when connected to the 75/15, or is it the battery voltage that drops?.

Are you certain the PV polarity is correct?

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kevgermany avatar image
kevgermany answered ·

PV voltage drop is normal, but this is quite large. What charger state is displayed. What are the charger settings?

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