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quimbola asked

Solar panel working correctly? 100/30 MPPT

Renogy 175 working correctly, help?


Hi all,

Looking for some help. I just installed a renogy 175 w, Victron 100/30 MPPT smart controller, 15’ of 12 AWG wire, 30 amp breaker between Battery and MPPT. At 1:00pm today in Colorado with no clouds in the sky here is my Victron reading.

1664139408085.png

This seems low. I have the Victron set to AGM battery and kept the default settings.

Do I have a bad panel, or is this what I should expect? What else can I check?

Thank you in advance!

-Josh

Solar Panel
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6 Answers
Sarah avatar image
Sarah answered ·

It is possible that you are getting a voltage drop across the cables that is impacting the power output. Measure the voltage at the battery to see what is going on. Also is it possible to test the install with a shorter cable run to the battery?

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quimbola avatar image
quimbola answered ·

I checked the voltage right out of the panel and it read 19.9, same as the app.

Anything else I should check?

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Sarah avatar image Sarah commented ·

@Quimbola Check what the voltage is at the battery and see if that matches the app. This will be indicative of voltage drop between the MPPT and battery.

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quimbola avatar image
quimbola answered ·

Hi Sarah, they match.

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nickdb avatar image
nickdb answered ·

At 21.6V that isn’t a lot of panel given the battery and the +6V requirements.

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Sarah avatar image
Sarah answered ·

@Quimbola not sure what is happening. The panel only just exceeds the +5 volt requirement so this could be a problem, Check to see that all your connection are tight and that there are no stray wires that could be shorting any of the connections. Also double check the default AGM settings compared to the battery manufacturers recommendations.

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nickdb avatar image nickdb ♦♦ commented ·
Max panel voltage is 21.6 according to the specs, so it was never going to be a good idea to have just one.
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klim8skeptic avatar image klim8skeptic ♦ nickdb ♦♦ commented ·

You have a valid point.

The Renogy 175 panel consists of 32 cells.

Below Victron's recommendations for panels having 36 cell requirement to charge a 12v battery.

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quimbola answered ·

Checking the voltage directly at the solar panel gives me the 19.9v, do you think it is a bad panel?

These are the panel specs:

Max Power at STC: 175W
Open Circuit Voltage: 21.6V
Short Circuit Current: 10.62A
Opitmum Operating Voltage: 18V
Optimum Operating Current: 9.73A

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Sarah avatar image Sarah commented ·
The problem may well be that you are not getting sufficient voltage out of the panel to operate the mppt charger - you need at least the battery voltage plus 5 volts. If this is the problem having two solar panels in series would solve it.
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