Detected a lie ! (producing wattage several hours after dark)

[mike90045]

Pic's from yesterday.  Day was mostly cloudy and rainy, but did have a few holes in the clouds that some sun punched through.
I'd been running the genset several times during the day for loads and charging via the integral charger in the the inverter.
But when I went to shut the genset down, I heard the inverter playing the "tunes" it plays when it's not got enough power to really  be charging, but too restless to go to sleep !  But this was several hours after sunset, pitch black, cloud cover and no stars or moon visible.
I'm running Legacy P/O mode.   I turned (via remote, unit is 900' away in heavy rain) mode to OFF and then back ON and things seemed OK (sleeping at  0 watts)  the rest of the night.  Today was similar conditions, mostly clouds, some spotty sun.
  What could be going on ?

[dgd]

The local app program stopped working and the display was stuck at the last time it had contact with the Classic.
I have seen this a few times over the last year. Closing and restarting the local app fixes the display.

dgd

[mike90045]

Local App was not stuck, it was dithering around 10-30 watts, and the graphic panel LCD read bulk when I heard it singing way past dark.

[boB]

Well, the Classic is supposed to turn OFF (go to Resting) when sitting below 20 watts for 90 seconds.

What obviously happened here is that the current offset got slightly whacky and so Legacy mode did not
shut off properly.  This is extremely rare as far as I know, Mike.  The current sense offset check is normally
extremely good.  In some charge controllers, the current sense can be very temperature sensitive.
The Classic has been perfected pretty much in that regard but once in a great while the offset
current when OFF and when it is just coming out of resting can get off.

Legacy mode will move around that PV input voltage but will not necessarily open up until

I think we can fix this by watching the output current for a while and if the wattage stays below
say, 50 watts for some length of time, maybe like 10 minutes, the Classic can do a reality calibration.

It should not be sitting very long with low power production which might indicate the issue you
had.

There is a new firmware beta coming up.  I will see if we can tack this fix in there.
boB

[mike90045]

It should not be sitting very long with low power production which might indicate the issue you had.

Sadly, the whole day was pretty low power (less than 100w from a 2Kw array), except when the sun briefly burned through the clouds for maybe a total of 20 minutes.  Forecast is for another 8 days of this rainy stuff.

I will look forward to a fix for this. 

I was in the battery shed, ramping down the charge from my genset to let it cool before total shutdown, and the multi-tone sounds from the inverter Classic caught my ear.  It normally does that for about an hour in the evening as its trying to make up it's mind about shutdown.

[boB]

I was in the battery shed, ramping down the charge from my genset to let it cool before total shutdown, and the multi-tone sounds from the inverter caught my ear.  It normally does that for about an hour in the evening as its trying to make up it's mind about shutdown.

Inverter ?   Which inverter ?  Or did you mean the CC ?

The Classic will sometimes make that noise when the PV input voltage is near the battery voltage.
This can be stopped, if wanted, by turning off LowMax in the Tweaks menu.

[mike90045]

I was in the battery shed, ramping down the charge from my genset to let it cool before total shutdown, and the multi-tone sounds from the inverter caught my ear.  It normally does that for about an hour in the evening as its trying to make up it's mind about shutdown.

Inverter ?   Which inverter ?  Or did you mean the CC ?

The Classic will sometimes make that noise when the PV input voltage is near the battery voltage.
This can be stopped, if wanted, by turning off LowMax in the Tweaks menu. 

Yes, i meant the classic CC was playing the tunes.   LowMax in the tweaks.  On it !
  Thanks,  it was ON, and now is off.  We'll see how it goes the next few days.

[Halfcrazy]

I have seen this a handful of times. If the Classic is making real low power and an "External" source is brought in to charge the battery the classic will stay awake into the night. I will rehash this with boB and see if he can find this issue

Ryan

[mike90045]

I have seen this a handful of times. If the Classic is making real low power and an "External" source is brought in to charge the battery the classic will stay awake into the night. I will rehash this with boB and see if he can find this issue
Ryan

Oh wow, I try to run the genset before dark, so I can shut it down, and walk back with the last vestiges of light.  We've had 2 weeks of clouds, and another week forecast of rain and clouds. Sun next year !   So there will be charging from the inverter when the generator is running.

[mike90045]

 Caught it again tonight.  It was well after dark, moon not up yet, and used a flashlight going to the generator.  I did not notice if this activity was going on before I started the generator, but I spotted it after I shut it down, when I was pulling the log data.   The local app was not "stuck or frozen"  The reading were twitching around. The buttons worked, the background was green, not yellow.

Hopefully the differences in the indicator meters can help diagnose what/how it's reading 80V on the PV array at night, with 57V on the battery (my normal NiFe range is 48-67VDC)  and then it's changing.

  I was able to get it to behave by turning (via LocalApp) solar charge (Legacy P/O) OFF, then back ON (for tomorrow if there is any sun) and it's currently behaving right.

[boB]

This next upcoming revision should fix this night time problem.  The input voltage is real though and comes from
the Classic up-converting the battery voltage.  The watts are not real though.  Some offset obviously.

What is causing your battery voltage to be so high at this time though ?  Were you running a generator ?
57.x volts is unusual for night time unless there is another charging source running

[mike90045]

My normal NiFe range is 48-67VDC.  It's pretty wide, but within the Midnight's range.  And, yes, I had started the generator after dark, and noticed the occurrence.