FoxESS Community - Owners & Installers Forum

Installers have now raised the remaining three issues I've noticed with Fox. I've sent some screenshots which will hopefully help Fox fix them:

1) Forced Charge imports at 2.82kW not 6kW as expected.
2) Forced Discharge imports at ~200W after the discharge target is reached even though there's solar and the battery is at 94%. Would expect it to switch back to Self-Use mode.
3) Minor issue with the app/web showing "Grid Importing" when the unit is obviously exporting.

elljay wrote: ↑Thu Mar 12, 2026 12:17 pm 3) Minor issue with the app/web showing "Grid Importing" when the unit is obviously exporting.

Would you have grid/meter compensation set at all?

When mine was set to 0 everything seemed fine display wise, but it was actually exceeding a 30Wh/hr import limit my plan comes with.

Since going under that limit using grid/meter compensation the import/export info is a bit weird at times.

evilbunny wrote: ↑Thu Mar 12, 2026 12:47 pm Would you have grid/meter compensation set at all?

Hi, not unless the installer set it, and I don't think they did. This is when the battery was force exporting 4.84kW and the display says "Grid Importing" ! The animated green arrow above the text moves towards the grid, which is correct.

From memory the 1.09 firmware used to say "Grid Importing" and "Grid Exporting" - the 0.23 version either says "On Grid" or "Grid Importing", so I guess maybe someone inserted a string rather than editing it ?!

evilbunny wrote: ↑Thu Mar 12, 2026 12:47 pm When mine was set to 0 everything seemed fine display wise, but it was actually exceeding a 30Wh/hr import limit my plan comes with.

Mine seems to import around 5-10W when it's at steady state. I read somewhere that the unit prefers to be importing a little bit so it can more easily tell if the grid fails. It annoyed me at first but then 10W x 24h x 365 days x 34p/unit is £30 a year... I can see it's an issue with a 30W/hr limit though..!

elljay wrote: ↑Thu Mar 12, 2026 2:15 pm I read somewhere that the unit prefers to be importing a little bit so it can more easily tell if the grid fails. It annoyed me at first but then 10W x 24h x 365 days x 34p/unit is £30 a year... I can see it's an issue with a 30W/hr limit though..!

For grid monitoring I was told/explained that it's an infinitesimally small amount from the grid to monitor it depending how close an implementation can get to the theoretical physics limit. It's a much smaller number than even 1Wh/year.

What really happens is loose CT clamps aren't overly precise so some power will go in both directions as the inverter can't tell exactly how much to discharge.

Grid/meter compensation attempts to counter the inaccuracy by constantly exporting, but as I've come to find out it may be impossible to completely stop importing.

Waiting on meter data for yesterday, but when it was set to -50W our usage was about 4c, at -60W it was 3c, and -70W was 2c, it seems to be a diminishing return at this point and it doesn't seem matter how low it's set it won't eliminate it totally.

Our imports are limited to 30Wh/hr between 6pm and 8pm and even when set to -50W it's well below that at ~4Wh/h, so might be better at about -30W instead.

Yup, there's going to be a delay betwen something turning on, the CT being polled and the inverter ramping up to meet the demand...

elljay wrote: ↑Thu Mar 12, 2026 2:59 pm Yup, there's going to be a delay betwen something turning on, the CT being polled and the inverter ramping up to meet the demand...

It must be quick and accurate enough that it can keep things to a few Wh/h, even without the compensation set only ~40Wh/h was being imported, but fractions of missed power start adding up.

Am I just unlucky or is Fox support rubbish?

Installer logs a case with Fox. Email back from a Fox "UK & Ireland Sales Director" who copies in three people in "the service team". A "Field Service Manager" requests a screenshot of the app showing the mode scheduler settings. Very confused because I included that in the email that was forwarded to Fox. Queried what they needed and got no reply. Sent more evidence of one of the issues (Force Charge reverting to importing 200W once the target was reached) and got a reply basically saying "That's the way it works.". Replied saying that there was nothing in the app, web or online manuals that explains how the mode works so not surprising I hadn't understood and suggesting a work around. So far no reply...

Since logging the issues I tried a 12kW Force Charge again and this time it charged the battery at 4.92kW rather than 3.05kW. No idea why it's increased. First time was at 11:52AM - second time 5:20AM so guess it's not due to temperature. First time battery SoC was 94%, second time SoC was 33% so maybe it's that...

Found another display bug - I've now made £13.38 from solar savings and FiT revenue according to the app, but the app shows it as either "1,338.26p" or "1.34Kp". Silly little issue but easily fixed...

The battery seems like a very nice product let down by being released to market before it's ready and with poor tech support...

elljay wrote: ↑Tue Mar 17, 2026 7:06 am Since logging the issues I tried a 12kW Force Charge again and this time it charged the battery at 4.92kW rather than 3.05kW. No idea why it's increased. First time was at 11:52AM - second time 5:20AM so guess it's not due to temperature. First time battery SoC was 94%, second time SoC was 33% so maybe it's that...

Take a look at Will's video here, see if you can bring some more logs to the fight

Your higher charge rate is more than likely down to temperature, check in https://www.foxesscloud.com/v2/login website and get up the Min Cell Temp for the charging times in question.

Interested in your findings.

Unfortunately I don't get the filter button... (Screenshot attached)

The two download buttons just give CSVs of the values shown in the graphs - battery temperature isn't one of them.

The "Real Time" tab doesn't show the bat temp or have any download/history option.

I'm downloading all variables from the history_query() API, but none of the temperatures available seem to match the currently reported 11.9C Min. Battery Temperature...

{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":41.8}],"name":"AmbientTemperature","unit":"℃","variable":"ambientTemperation"},
{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":0.0}],"name":"BoostTemperature","unit":"℃","variable":"boostTemperation"},
{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":33.8}],"name":"InvTemperation","unit":"℃","variable":"invTemperation"},
{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":0.0}],"name":"ChargeTemperature","unit":"℃","variable":"chargeTemperature"},
{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":30.7}],"name":"batTemperature","unit":"℃","variable":"batTemperature"},
{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":0.0}],"name":"DSPTemperature","unit":"℃","variable":"dspTemperature"},

Had a quick look at v1 dashboard but nothing obvious there.

It might be in one of the other APIs but there's nothing's obvious... Any ideas where else to look?

And looking at the data "Ambient Temperature" is rubbish! It's about 11C outside...

{"data":[{"time":"2026-03-17 10:31:01 GMT+0000","value":41.8}],"name":"AmbientTemperature","unit":"℃","variable":"ambientTemperation"},

If Min. Bat Temperature is close to the outside temperature then the first test was run at about 9C and the second at about 9C as well...

There have been occasions where the filter button can come and go
Try later or another browser.
As you have a fairly new EVO, there might not yet be the full logging available.

As for your mad high ambient, was the Sun hitting your Inverter?

MaterialBarracuda48 wrote: ↑Tue Mar 17, 2026 11:11 am There have been occasions where the filter button can come and go
Try later or another browser.

Heh, sounds like Fox's motto - "It might work or it might not!"

MaterialBarracuda48 wrote: ↑Tue Mar 17, 2026 11:11 am As you have a fairly new EVO, there might not yet be the full logging available.

It was activated on the 6th so eleven days now... I did just try and download the history for the 10th through the, err, device_history API, but it came up as all zeros. But maybe last week's web outage zapped something...

MaterialBarracuda48 wrote: ↑Tue Mar 17, 2026 11:11 am As for your mad high ambient, was the Sun hitting your Inverter?

Nah - sun's only just come out from behind the clouds today... It's definitely not 42C outside!!!

Funny stuff indeed

Not sure about where the Ambient sensor is located, but in a cold garage with no Sun, it sits nearly always above 30°C day or night. Currently at 33°C, and the garage will be cold for sure.

Wondered if maybe it was reporting in Farenheit, but the dashboard is currently showing 12.8C which is 55F and the API is reporting 43.5 which would be 6.1C...

elljay wrote: ↑Tue Mar 17, 2026 11:22 am Wondered if maybe it was reporting in Farenheit, but the dashboard is currently showing 12.8C which is 55F and the API is reporting 43.5 which would be 6.1C...

At least it was not in Kelvin, that would be brutal

MaterialBarracuda48 wrote: ↑Tue Mar 17, 2026 11:23 am At least it was not in Kelvin, that would be brutal

Brrrrrrrrrrrrr!!

Just for fun this is what the API has been reporting for temperatures over the last day or so. The 6PM peak is when it was exporting to the grid at ~5kW...

Hello, new user and first post!

I too have recently had the Evo 10-5 installed (13th March) and it was fully commissioned the Friday after.

I have completely failed to manage a force charge on the Octopus over night cheap rate so far. I have managed today to achieve a scheduled force charge using the instructions in this thread, so thank you!

However, I also have the same issue in that the force charge in the day draws from the solar, tops up with grid to the 1.06kW and puts the rest of the house on grid too.

Did the firmware update resolve the cap on force charging at this rate? I did a firmware update on Friday but I am still on version 1.09.

Hello and welcome! Glad the thread helped!

Yes the update to INV_Master v0.23 has resolved most of the issues. Given the version number starts with a zero and it's a lower number than the 1.09 that appears to the latest version it makes it look like a beta version. The app tells me there's "1 Upgrade" available but obviously I haven't "upgraded" it back to v1.09!

The only issues I'm seeing now are some silly formatting on the Revenue amounts but all the major functions now work. The only other niggle is that once Forced Discharge reaches the target level it sits there importing at about 200W till the end of the period rather than reverting to Self Use. I couldn't see any detail about the mode in any of the documentation and Fox's curt reply was "It's working as expected". I did ask them to point me to a description of the modes but they didn't reply. My workaround is just to set the target lower than I expect it to reach and adjust the Discharge Power so the SoC doesn't go too low.

To get v0.23 my installer called Fox and the lady talked to a colleague and then pushed v0.23 remotely to the unit. It was complete in about 20 minutes.

I guess Fox will issue a new version with a higher version number than 1.09 at some point that incorporates whatever changes they've made in 0.23.

I was in email contact with various people at Fox but they are useless at replying and didn't seem to understand the issues I was raising so given the unit is mostly working I haven't bothered chasing them...

I've been working on getting Modbus over WiFi working so I can query the unit more often than the five minute updates via the API. If anyone's interested I can post more detail / code etc...

Thanks for the reply.

It’s good that it sounds resolved and for the moment I am not overly worried about the slow charge rate, as long as it actually does it!

It will definitely be more of an issue in winter when I will be wanting to charge the full 9kW every night, at the moment I am aiming for 55% and hoping the sun tops off the rest in the day. With the settings way they are I should just about achieve that at the 1.06kW rate!

When I get DNO approval I will be switching to full force charge too, so fingers crossed the new firmware appears soon.

These are the current settings I have, I would be very great-full if you could give any feedback or spot any errors. I had no idea what an ideal wattage is so went for 6kW like my EV charger Really hoping to see some charge in it tomorrow morning and not just 10%.