Using Grid power instead of Battery on Self-Use mode?

[Leokem]

Hey people!

New Fox user here, enjoying the new solar life!
I have a question: I've been monitoring the system from time to time and the Inverter sometimes choose to charge the battery (5.2kW) instead of using when we have higher loads, here are a couple of examples:





Is this normal? It's only until the data update itself (please give us real time data Fox!) and it goes back to pulling from battery if solar is not available.

Thanks!

[Dave Foster]

I think what you are looking at is data latency of the website - if a large load turns on or off the inverter has to source the load from pv/battery/grid to match - this often results in a very small time window where the grid is used to fill the gap, before the battery takes over. Likewise when a large load turns off, you sometimes see export again for a second or 2 before the inverter has the chance to adjust it's loads.

As the data 'snap shots' every 5 minutes you sometimes get strange looking traces (like this) where the system is mid change - If it settles down on the next 5 minute cycle then it is very likely this, it is better to view the graphs as they show the trend of the power usage - if it is higher than you expect on there, it's time to investigate.

If you have access to the inverter panel, it gives you a real time display of the amount of power currently being generated or used (+/-), always helpful if you think something isn't looking right.

Just as an aside, if you are a new user I would highly recommend using the Energy Stats app from Al Priest - it's considerably more user friendly than the Fox app and provides more meaningful information.

You can get it from the Google Play Store at https://play.google.com/store/apps/deta ... 7QFKeeQE5w and if you’re on iOS you can get it from the App Store at https://apps.apple.com/gb/app/energy-stats/id1644492526

[Leokem]

I think what you are looking at is data latency of the website - if a large load turns on or off the inverter has to source the load from pv/battery/grid to match - this often results in a very small time window where the grid is used to fill the gap, before the battery takes over. Likewise when a large load turns off, you sometimes see export again for a second or 2 before the inverter has the chance to adjust it's loads.

As the data 'snap shots' every 5 minutes you sometimes get strange looking traces (like this) where the system is mid change - If it settles down on the next 5 minute cycle then it is very likely this, it is better to view the graphs as they show the trend of the power usage - if it is higher than you expect on there, it's time to investigate.

If you have access to the inverter panel, it gives you a real time display of the amount of power currently being generated or used (+/-), always helpful if you think something isn't looking right.

Just as an aside, if you are a new user I would highly recommend using the Energy Stats app from Al Priest - it's considerably more user friendly than the Fox app and provides more meaningful information.

You can get it from the Google Play Store at https://play.google.com/store/apps/deta ... 7QFKeeQE5w and if you’re on iOS you can get it from the App Store at https://apps.apple.com/gb/app/energy-stats/id1644492526

Thanks for the reply, Dave!

It seems that this could be the case, but I would still need more data to confirm it. I appreciate the time and the app recommendation, will check that as well!

[srooke]

I recently had an H3 Pro system installed. Our inverter was operating as expected in Self-Use mode for about 2 weeks. However, for the past week it has used the grid instead of the battery for the majority of the night. I cannot figure out how to fix this.

Current settings:
+ Mode: Self-use
+ BRC: 20%
+ Min. SOC: 10%

Firmware:
Master: 1.007
Slave: 1.07 (except one battery that is still on 1.06)

The battery will intermittently switch over with huge spikes and then switch back to the grid. I feel like there may be a significant issue with the battery. It is currently at 82%, but only discharging 5-20W.

Any thoughts on how to fix this?

[calum]

What are the ambient temperatures where you are? The batteries being cold can have an effect on their ability to deliver power.

[Dave Foster]

Just to add to the list of common causes of battery not being used -

Do you have a charge period set ? - if they are set to *anything* other than 00:00-00:00 even with the grid charge switched off they will not discharge so double check the charge periods are set correctly or are left at 00:00.

Does your home load power report correctly ?

Is there any pattern to the spikes you are seeing, a certain time of day (dawn/dusk) a particularly high load ?

Are there any errors reported in the logs ?

It’s good practice to have all of the slaves the same, but they look like older firmware versions, which batteries are they ? - I can look up latest firmware versions.

On the Inverter itself, what firmware versions are you on - the H3 Pro is new and there have been recent firmware releases - Master is currently 1.28, Manager at 1.12

[srooke]

Thanks again Dave!

I’ve checked the settings and they are all as you described. I cannot identify any particular pattern, except that it worked correctly until about a week ago.

There are no errors in the logs.

[Dave Foster]

Thanks again Dave!

I’ve checked the settings and they are all as you described. I cannot identify any particular pattern, except that it worked correctly until about a week ago.

There are no errors in the logs.

Hmm, ok, I can’t remember whether the H3 Pro has got schedules yet - if it does, there are no force charges or work modes set ?

Once you’ve looked at that, as you have received the latest firmware - it might benefit from a full inverter restart so I would be inclined to try that and see if that recovers the situation.

To restart (power off/on) you will need to first isolate the PV (DC), then isolate the AC (grid), then finally power off the batteries - the inverter screen should go blank after a few seconds, then wait 10 seconds and reverse the order - batteries on, AC on, PV (DC) on. The inverter will check itself for a few minutes then resume normal operation, which should mean running off battery !.

[srooke]

Correct. There is no mode scheduler feature yet for the H3 Pro. It’s currently “disabled” and clicking on it triggers and error saying “not supported.”

I’ll try the hard restart and see if that fixes it.

Thanks for your help again.

[srooke]

What are the ambient temperatures where you are? The batteries being cold can have an effect on their ability to deliver power.

26.6° C. So well within the product specifications for temperature.

[srooke]

I just checked my inverter and noticed something strange from yesterday. It looks like the inverter is only using the battery when the PV is active.

1) We were on the grid overnight
2) As soon as there was voltage on the PV, the inverter switched over to the battery
3) The battery discharge went down as the PV power went up to fill the gap with the load
4) As the PV power went down at the end of the day, the battery discharged again to offset the load
5) When the PV finally had no voltage, the inverter switched from the battery back to the grid

Is it possible that the inverter would function like this? For the first 10 days that we had it, the self-use function worked properly with the battery discharging to the reserve amount before switching over to the grid. But now it seems like the inverter is only engaging the battery when the PV is on, otherwise it switches back to the grid.

NOTE: I still need to do the hard restart. I am currently out of the country, but should be back on Saturday.

[Dave Foster]

It’s not a normal operating mode, i’ve seen it do something similar when the mode is set to feed-in first but only when there isn’t enough solar power and the battery fills in a bit - but you are in self-use ?…

I suppose it might be worth trying to change the work mode to be feed-in first, leave it a few minutes and then switch back to ‘Self Use’

If not lets see how it behaves after a full restart and we can investigate further

[srooke]

I wanted to provide a quick update:
+ Changing modes did not have an effect
+ So we did the hard reset on Monday
+ We also moved PV3 to PV2

The solar data is now showing correctly for the second set of panels both on the inverter and the app.

The data feed for SOC is still not logging in the app (ie shows as zero in the chart despite reporting correctly elsewhere in the app).

The battery now seems to be discharging as expected in self-use mode.

Thank you for your help!

[srooke]

Just flagging that this issue returned about 4 weeks after the hard reset. Will restart again. Any thoughts on whether this is a software issue or if there is a problem with the inverter itself?

Just looking at the data, it seems like around 28/4 it hit the SOC minimum and switched over to grid (correct function) and then it never switched back. It's almost as if the inverter's state changed because of the SOC settings, but then forgot to change back to the above-minimum-SOC state.

Manually toggling between states will fix it, but then at midnight it's like it switches back again.