Question 18kpv every morning powers load with pv but wont send any to batteries until inverter restart.

It appears that the system is currently charging the batteries and powering the loads. Are you able to leave it running without adjusting any settings? This way we can gather accurate data and ensure nothing is being changed in the settings that would cause this.

It is currently charging the batteries but does not start to do so without my interaction every morning.  I will leave it untouched through tomorrow morning and reach back out.

For reference, below illustrated a typical load/charge scenario where it worked correctly.  My loads are automated so they are always the same and the battery is usually fully charged by mid day.  The second illustrated this new problem where the PV ramps up to cover the loads but never begins charging the battery until mid day when I notice it and manually intervene, either changing the Off Grid setting or rebooting the inverter. The second day was light scattered clouds but it should still have the basic pv charging outline as the top graph with momentary cloud spikes as it does the second half of the day.

Of course, this morning it did not seem to do it.  So its intermittent.  

No worries! We can keep an eye on it, if it does happen again just let me know and I can take a look. 

So this morning it appears to be doing it again. When the loads turned on, solar immediately jumped 2500watts to meet the load but had not been using that to charge the battery. Now the solar production is only following the load and not charging the battery.  I am in Off Grid mode but cut over to Grid due to low SOC. My loads should be going through EPS, but it hasn't switched back over due to not charging the batteries back up.

So it finally switched over to EPS on its own at 1:01pm then back off and back on again at 1:09pm when if finally stayed on and started charging the battery.  I looked at all my settings and do not have anything set anywhere near 1pm but found it odd it was so on the hour. Up until that point it used PV to follow the load only with no charge to the battery.  It was full sun all day with no clouds until almost sundown.

It did it again today but I couldn't leave it that way and miss another day of charging. It seems like in Off Grid Mode, once the battery gets down to the cut out SOC and switches to the grid, it wont charge the batteries from PV until some random criteria occurs long after PV is plentiful. And once it does finally figure it out, its is only momentary at first, switching back to grid and in failure mode again. I had to reset the inverter to correct it.

What batteries do you have and how many?

I have a single Eg4 15k indoor battery.

It did it again this morning.  Battery was depleted down to 12% (battery cutoff is at 10% which had happened), in Off Grid Mode, EPS relays were off and it was powering loads with the grid.  Solar production matched the load and it never started charging the batteries.   I once again reset the inverter.  EPS relays were on, and PV began powering both the loads and charging the battery.

As an additional test, I waited a bit for the battery to get up to 18% then turned off 'Off Grid Mode'.  EPS relays turned off, PV continued to power the load but battery charging stopped and would not continue.  This all started with the latest firmware, and I noticed this firmware has a line item that addressed this very issue with the GridBoss: 

• 16.Improved stability when switching between on-grid and off-grid modes if the battery discharges to the On-Grid Cut-Off SOC/Voltage while running with GridBOSS and set to Off-Grid mode.

I waited a bit to get some logs. Since I need the battery to be charged, I switched it back to Off Grid Mode, the batteries immediately began charging.

Off Grid Mode On after Restart

Off Grid Mode Off

So I have narrowed this down to a logic problem in the inverter related to working modes. One with the AC Charge mode time window and the other when the battery reaches the Off-Grid Cut-Off SOC(%) and the EPS goes into Standby and switches to Grid use . 

Off Grid is Enabled. If I disable all working modes and have the inverter set to self consumption, the inverter works as expected in Off Grid Mode regardless if the EPS is in Standby or not. When PV becomes available, it offsets the grid use first then any excess is sent to charge the battery.

Problem 1:

If I enable AC Charge Mode with a time window, the first problem is the charge window is not honored. If the battery drops below the Start AC Charge SOC(%) then it will charge up to the Stop AC Charge SOC(%) regardless of what time is in Battery Priority Start Time 1 / Battery Priority Start End 1 and what the inverter time is set to.

The only way to prevent AC Charge Mode from charging from the grid outside of its Battery Priority Start Time 1 / Battery Priority Start End 1 is to set Peak Shaving Mode to the remainder of the time outside of AC Charge Modes Battery Priority Start Time 1 / Battery Priority Start End 1.  And this works to limit charging to only that specific window.

Problem 2

The 2nd problem is that when the battery reaches the Off-Grid Cut-Off SOC(%) and the EPS goes into Standby and switches to Grid use, and AC Charge Mode is enabled, any excess PV is not sent to charge the battery and the amount of PV drawn matches the load. I have noticed 5-60 watts reported as charging the battery during this time intermittently but this may be a misreporting. This remains true for as long as the battery SOC remains below the Start AC Charge SOC(%).  With nothing charging the battery, EPS remains in Standby, this could be for the entire day.  Only resetting the Inverter breaks it out of this faulty state, it switches EPS back on and begins charging the battery from PV while also powering the loads as expected.