question

So, no led light up?

Can you query the mppt with Victron Connect?

Hello, it seems i'm facing the same issue with my MPPT 75/15. Everything was going well before firmware upgrade to 1.56 but since i made this update, the solar current/power seen from MPPT is very low, rarely more than 1A (usually 0 ou 0,2A). MPPT stays in bulk mode but doesn't really charge the battery. Icc current and voltage in open circuit on PV are correct. I'm then intersted with expert answers. I wonder if there's a way to downgrade firmware (at least to validate the origin of issue) Thanks

I will test the solar panel output when I return to my RV on the weekend. Its just super suspicious that It worked absolutely flawlessly until the moment the firmware was upgraded.

Here are some screenshots showing the issue: This one shows the firmware currently on the MPPT.
This one shows when the firmware was installed and the effect, look at 8 days ago:

Another shot showing how the charge controller stopped charging The battery bank was just installed in the RV 28 days ago after the winter.

This is the output from solar panel in bright sunshine and charge to batteries

Meanwhile this is the voltage present on the batteries:

Here is the log file downloaded from the replacement MPPT controller:VictronConnect_report.log

Hi,

Any luck with resolving this? I'll start a new thread but seem to be experiencing a very similar issue with a 100/20.

Thanks.

I tested the Solar Panel output and measured 47.61v but no ISC current. Short Circuit current should be 10.82 A in ideal conditions. Found out the fuse in the meter I had borrowed was blown I will return again this weekend to the RV with another meter and complete the testing. My Fluke meter only measures up to 10 A so I have borrowed one that will measure up to 20 Amps.

The setup in the RV is a new 395 watt Canadian Solar panel that connects to the Victron Smart Solar MPPT 100/20 48V. The battery leads go to the Inverter control sub panel where they are fed to the battery bank (4 x Trojan T105 plus lead acid). The inverter is an older 3900 W Heart (Now Zantrex) device that controls the battery charge and power input connections from the Onan 4KW generator. I upgraded the solar panels last year and switched to from PWM controller to the MPPT controller. The wiring is the same as before I merely switched the solar panel and battery wires from Old to new and it worked like a charm.

Everything was working very well since last July and the batteries were always maintained at full charge until the firmware was updated on the MPPT controller. All of the other things work perfectly the inverter produces AC and the Onan generator produces AC that feeds in to the shore power 30 Amp plug.

I will confirm working PV output and ISC current is close to spec for the panel with the PV disconnected from the controller. I will also confirm battery voltage on the battery leads when disconnected from the controller.

Problem resolved!! I discovered a blown fuse in the line from the charge controller to the battery bank. When I upgraded the solar panels and charge controller I did not realize a 15A fuse was placed inline to the batteries. (there was no schaematic of the solar/inverter/generator setup) I Replaced the fuse with a 20 A and problem was resolved. I guess it was a coincidence that the day I upgraded the firmware on MPPT to ver1.56 was a very sunny day when the current to my batteries exceeded 15A and took out the fuse.

Thank you Victron Community for your help.