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taiyoken avatar image
taiyoken asked

MPPT 100|50 not charging and PV voltage drops below Battery voltage

Hi There

My system is pretty simple.

I've got 2 solar panel in parallel and its connected to the mppt PV port and the batteries connected to the Batteries port on the mppt.

this system was working perfectly for almost a year until recently I noticed that there no longer any charge coming from the PV. At first I assumed cloudy weather but then on a very sunny day its still not charging. And I noticed that the PV voltage on the Mppt was slighty lower than the battery voltage. So I decided to restart the Mppt by power cycling it. It started working for about a week before it did the same thing again.

This time I assumed it was a faulty MPPT, Hence I replaced it with a new one but the result is still the same.

I even disconnected the Solar panel from PV. and I measured the Solar panel voltage with a multimeter and I was getting 35V and climbing on a sunny day, but as soon as I connect it to the mppt PV port the voltage drops. I even measured the PV terminal and it was a drop.


Any Ideas what it could be?

If it was a loose connection then how am I getting a voltage measurement on the meter if there was a loose connection (Open circuit/ broken circuit)


Also this was done after updating firmware.

thank kindly if anyone has been through this


Kind Regards

Albert


MPPT SmartSolar
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3 Answers
Paul B avatar image
Paul B answered ·

maybe change your panels to a series connection, also if there is a bad connection then the voltage will drop greatly after the bad connection when load is applied even a small load - and then the voltage will return to a higher value if the load is removed Ie the panels are disconnected from the mppt

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Michelle Konzack avatar image
Michelle Konzack answered ·

I agree, you have a 100V MPPT and if your twi panels are identicaly and the Voc + 10% is smaller then the 100V you should put em in series which give you a significant higher output

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seb71 avatar image
seb71 answered ·

And I noticed that the PV voltage on the Mppt was slighty lower than the battery voltage.


I even disconnected the Solar panel from PV. and I measured the Solar panel voltage with a multimeter and I was getting 35V and climbing on a sunny day


What is your battery voltage?

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