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emmaanders avatar image
emmaanders asked

Smart Solar MPPT 75/15 not charging

We are using the Smart Solar MPPT 75/15 and 180W solar panel with one Lithium LIFEPO4 and it stopped charging after working without any issues for 2 weeks. When measuring the voltage from the battery at the inlets in the regulator it shows 13.14 V. That is not the same as showing in the app (see screen shot). When connecting the Blue smart charger 12V 50A to the battery after disconnecting the regulater there was no problem charging the battery. When measuring the voltage from the solar panel without having it connected to the regulator, it shows 22V. Our assumption is that the solar panel is not the problem nor the battery since it is possible to charge the battery with the battery charger. Any suggestions what to do?

MPPT SmartSolar
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2 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Checked the fuse at the MPPT right next to the connection terminals?

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emmaanders avatar image emmaanders commented ·

Thank you for your reply!

We tried changing the fuse, reconnect the wires and reconnect the solar panel and now it kind of works, it charges for a while and then stops for a little while and then starts charging again...

So I guess it's something wrong with the cable connected to the solar panel.

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klim8skeptic avatar image klim8skeptic ♦ emmaanders commented ·

Post a photo of your solar panel's label, or a web link to specsheet.

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emmaanders avatar image emmaanders klim8skeptic ♦ commented ·

Okey here is the label!

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klim8skeptic avatar image klim8skeptic ♦ emmaanders commented ·

HMmmm...

Label looks ok until you look at "system voltage" 45 vdc...

The manufacturer/reseller have probably overstated the panels rated specs..

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emmaanders avatar image emmaanders klim8skeptic ♦ commented ·

Thank you for replying! I think we've stated that the problem is a loose wire connected to the solar panel. Thank you again for your suggestions!

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Trina avatar image
Trina answered ·

To be clear; the problem is as in the first screenshot which is adequate voltage and bulk-phase charging but 0 amps.

You have good fuses and mppt is switched on (in charger mode) and has correct setup for your battery so the voltage is enough to begin the bulk charge and sunlight is also strong but no amps coming from panel?

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