Victron Charge Controller--Aberrant Readings

JEB

I recently replaced the Victron 75/10 charge controller in my 2019 T@B 400 with an upgraded Victron 75/15 to try and eke out a few more amps during boondocking.  Unfortunately, since the swap, I have been getting extremely odd readings from the Victron app and was hoping for help in diagnosing what I might have screwed up during the swap. 

Below is a screenshot of what I'm seeing.  As you can see, on the input side the app is reporting 0W and no current from the solar panel but positive voltage of 31.55V.  On the output side, it's showing the charge controller in float mode at 13.39V.   The output side is not surprising.  The batteries are fully charged because I keep the T@B plugged into 30A shore power.  The input side, however, is odd.  The previous charge controller showed positive watts, volts and amps even when I was plugged into shore power.  I took a look at the history chart and it appears that the results I see below have been consistent since the replacement.  Any specific help diagnosing the problem (beyond calling the manufacturer)--if it is a problem--would be greatly appreciated.  Thanks in advance.

Cbusguy

It makes perfect sense.    Watts = Voltage X amps.   Looks like you have zero amps and your battery is at capacity float charging.  Is it a problem?   The thing is just a calculator with a bit of memory is all.

JEB

That helps.  I understand the equations.  My concern is that this charge controller is reading completely differently from the 75/10 I just replaced.  It would show positive watts and current from the solar panel even when the batteries were fully charged.  If the old one was undersized and never got the batteries to kick over to a completely "full" charge, and therefore the solar panels were always outputting some current as a result, that would make sense.  I'm just trying to confirm that that's what's happening.  

Sharon_is_SAM

Did you program it or did you just swap it out?

JEB

I’m not sure I understand the question.  I swapped it out, accessed the controller using the app, updated the firmware, and then set the battery settings to the values I had previously.  If that’s what you mean by programming, then yes, I programmed it. 

Sharon_is_SAM

Yes, you programmed it.  So, since your battery is full and the current draw is so very limited, the solar panels have no need to feed the battery.  So the controller is just reflecting the available pre-controller voltage.  If you want to see if it is working, I would take it off shorepower, turn your battery switch on and turn everything on.  Then see how it changes.  My 2 cents!

JEB

Turns out it was a bad inline fuse on the solar panel side.  I pulled the battery-side inline fuse and inspected it and it looked fine.  I then pulled the solar panel inline fuse and it looked fine as well, but when I reinserted it into the holder it immediately blew.  So, I pulled both fuses again and waited about 20 minutes.  I then started with the battery side and it worked fine.  Solar controller powered up normally.  I then replaced the inline fuse with a new one on the solar panel side and it too went in normally.  No popped fuse.  When I checked the app, everything was back to normal.  About 90W of power on a partly cloudy day and just under 3 amps delivered to the controller.  The voltage was also down to a normal approx. 24V on the solar side. 

Best I can tell, the solar side inline fuse was either not properly seated or had blown only part of the way, which allowed the charge controller to register aberrant voltage leaching through the fuse but not enough current was passing to register amperage and therefore wattage.  In any event, it appears fixed.

Thanks to everyone who chimed in.

For those interested in the future, battery state of charge (SOC) appears to have nothing to do with what the charge controller registers on the solar panel side.  The panel side is just an input measuring what the panels are generating, not what is being passed to the batteries via the battery side.  So, if there's sunlight, you ought to be reading wattage and positive amps regardless of the battery SOC if the panels are operating properly.

NorthIsUp

How to I program my non-oem 712 to show solar? I just have the battery reading on down....

Sharon_is_SAM

Never would have considered the fuse!  Good call @Jeb!

JEB

NorthIsUp said:

How to I program my non-oem 712 to show solar? I just have the battery reading on down....

You can't.  It's a battery monitor, not a solar charge controller.

JEB

Sharon_is_SAM said:

Never would have considered the fuse!  Good call @Jeb!

Thanks.  Blind squirrel. . . .