No PV Voltage - SmartSolar MPPT 75/15

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kman asked Jun 25, '23

No PV Voltage - SmartSolar MPPT 75/15

Greetings!

I recently bought a new camper that came with a SmartSolar MPPT 75/15 controller installed and hooked up to a 185W panel and then to a 12V lead acid deep cycle marine battery. Seems like a fairly straight forward setup.

I installed the VictronConnect app and it performed all the firmware upgrades.

When I connect my panel to the controller, the app reads 0W, 0.01V, 0.0A.

I have verified with multiple multimeters that I am getting 29V through the connections from the panel. I also get a blinking "Bulk" light. It blinks every 5 seconds. I tried looking this up and while I can find things about blinking bulk lights for my model (3 LED, by the way) with frequencies from "rapid" to 3 seconds , I don't see anything that says what a 5 second blink means.

I've check all the fuses.

The one thing I'm not seeing is in the app battery settings an option for a wet or acid battery. I've tried all the presets with not luck.

I've been working on this for a week and even took the camper back to the dealer/service department and they are stumped (after trying everything I've done).

If anyone has some insight I would be extremely grateful.

-kevin.

MPPT SmartSolar Solar Panel

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seb71 answered · Jun 25, 2023 at 06:27 AM

When I connect my panel to the controller

Did you check the PV wires polarity (not just the voltage) with a multimeter?

Going by the PV wire colors, it looks correct, but sometimes people use wrong colors.

The battery positive wire is black in your photo and the PV negative is also black.

Reversed polarity on the battery terminal destroys the MPPT, so the battery wires are either correct or not actually connected.

With the PV wires removed, do you still have voltage on the battery terminals of the MPPT?

Have you tired a MPPT reset (disconnect PV, disconnect battery, wait 3 minutes, connect battery, connect PV)?

The MPPT fuse is OK?

Also your screenshot shows 1:26 time. Is that in 24h format?

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kman answered · Jun 26, 2023 at 05:48 PM

Annnnd I knew it was something silly I was missing.

In the wiring connector pouch that came with the unit there was what I thought was an extender and since I was able to connect directly, I thought it was an extraneous part.

Turns out it was a "crossover" connector that reverses the polarity. I used this part and bingo!

Again, thank you for the questions that spurred me on to the polarity issue!

-kevin.

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Answer 1 · 2023-06-26T16:22:10Z

kman answered · Jun 26, 2023 at 04:22 PM

Many thanks for the reply!

You bring up many good questions. The battery cables, though unconventional seem to be correct. (Note: this was how I bought the unit)

I do have battery voltage to the MPPT (and can see it update in realtime on the app) without any connection to the PV.

I did try the reset after your suggestion but still no change in thesolar power reading on the app.

BUT - based on your prompt about checking the polarity of the PV wires, I took a second look and it appears that they are indeed backward:

I'm going to ask the dealer to change this (so as to keep my warranty!) and see if it fixes the problem. I'll report back when we do this.

Thank you very much for your great questions!

-kevin.

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