FoxESS Community - Owners & Installers Forum

Hi i am new to the forum. A month ago i installed a Fox ESS SQ 4800 with 42 kw Battery. I have a 10 kw H3 inverter. I am enrolled with Amber Electric VPP.
For the first 4 weeks it has been working fine. I use Amber on Smartshift Auto mode but also use manual commands. Over the last few days my Battery has failed to discharge except for house loads overnight. My Fox Cloud had no mode schedule set. The Amber App said a communicarion error with Fox ESS. Everything on the Fox App said online.
I did a full WLAN reset using the inverter and mobile app. Did not work. So i disabled the Amber Automation. Then attempted to use the Fox Mode Sheduler. Again it failed to discharge. I was careful to press both submit and confirm. The battery failed to discharge. The only thing i changed befor this issue started was the Battery Reserve Capacity was lowered from 20% to 15%. Interestingly every time i had previously tried this the Reserve Capacity always reverted to 20% as the app refrehed. But not this time. It remaied at 15%.

When you are using schedules or linked to a VPP such as Amber the scheduler will not allow the battery reserve to be changed.

When you say the battery failed to discharge, are you using a Force Discharge schedule to discharge the battery or is it that your battery is not discharging to meet the house load ?

If you are using schedules, could you screen shot the schedules in the app and add them to this post (click the 'Attachments' tab below the post and the the 'Add files' button)

The battery would only charge from solar and discharge from houshold loads. It would not discharge to grid on the Mode Sceduler on the FoxCloud 2.0 app or manual or atomatic commands on the Amber Smart Shift App.

This morning i phoned the Fox ESS suport line and discussed the issue. Apparantly the Firmware needed to be updated. They did this for me and told me to try it again in 1 hour. The problem is now fixed. The Fox support line was good, particularly considering the time of year. The thing that irks me is this. If Fox ESS bring out new firmware. Why don't they automatically update the affected battery systems. Alternatively they could send a message telling us to call customer support to have the firmware updated.

The reason Fox don't roll out firmware upgrades to thousands of systems is that it could brick/break systems and such.
It could be close soon that we can update the firmwares ourselves, this itself is not without it's risks.

Meanwhile, I am glad to hear Fox support was rapid, and solved your issue, let's hope it works perfect for you from now on.

@Alasdair65 and @MaterialBarracuda48 - thanks for the tip. I've been facing this issue since a couple of weeks (and have installed the battery too recently). Was waiting for the holiday season to end before i take this up with fox. Will do that tomorrow to see if it helps solve my force discharge not working too.

FYI my setup - Fox ESS 42.2kwh pack with Hybrid 10kw H3 inverter, AC coupled, myenergi Zappi.

skpmlbfox wrote: ↑Thu Jan 01, 2026 10:27 am @Alasdair65 and @MaterialBarracuda48 - thanks for the tip. I've been facing this issue since a couple of weeks (and have installed the battery too recently). Was waiting for the holiday season to end before i take this up with fox. Will do that tomorrow to see if it helps solve my force discharge not working too.

FYI my setup - Fox ESS 42.2kwh pack with Hybrid 10kw H3 inverter, AC coupled, myenergi Zappi.

Good luck, hopefully it all goes well for you when you contact Fox

Alasdair65 wrote: ↑Mon Dec 29, 2025 1:50 am The battery would only charge from solar and discharge from houshold loads. It would not discharge to grid on the Mode Sceduler on the FoxCloud 2.0 app or manual or atomatic commands on the Amber Smart Shift App.

This morning i phoned the Fox ESS suport line and discussed the issue. Apparantly the Firmware needed to be updated. They did this for me and told me to try it again in 1 hour. The problem is now fixed. The Fox support line was good, particularly considering the time of year. The thing that irks me is this. If Fox ESS bring out new firmware. Why don't they automatically update the affected battery systems. Alternatively they could send a message telling us to call customer support to have the firmware updated.

I have the same issue. I suspect the issue started when I upgraded to firmware Manager 1.23 from 1.18 and Master 1.36 from 1.30.

Please let me know your firmware version where you resolved this issue. Also appreciate advice whether the firmware can be rolled back to a previous version as there was no issue feeding back to the grid with manager 1.18. Except couldn’t change battery reserve down to 15% from 20%. Thank you

Hello everyone
I've just had my Fox 5kW inverter + 2x EP12 batteries (~20kWh) installed on the 18th December. I'm on Octopus Intelligent Go for my electricity, so can charge my batteries overnight ; goes along with my Volvo CX40 with the Ohme charger.

Everything was running fine until yesterday (3rd Jan) when I thought I'd try the "Mode Scheduler" - I'm thinking that Octopus Agile might be cheaper . I could use the batteries to avoid the "peak" rates around tea time and the day rates (on average) seem to be cheaper. My household uses over 40kWh per day so I need to limit when the batteries would be used if I switched to Agile - hence the trial of the "Mode Scheduler".

So, I set up my "Mode Scheduler" as: I've tried these settings via the app, the web site and also via the API. I get everything telling me this schedule is set , yet the battery do not appear to be discharging and they appear to be 55% capacity. See this picture:
https://www.dropbox.com/scl/fi/4ysg8nub ... 1ivj3&dl=0

Model：H1-5.0-E-G2-WL
Datalogger：605H502059FP128
Version_Master： 1.40
Version_Slave：1.04
Version_ARM：1.26

Quick update - on the morning of the 5th , the batteries have not charged overnight.
Anyone have any ideas on why the batteries are not sending power to my house? Or should I just contact Fox support?

You are using the v0 scheduler interface which is deprecated and doesn’t work with the extra parameters, try using this one instead https://www.foxesscloud.com/public/i18 ... 33e203ca3e

Or better yet delete the schedule and re-create it in the V2 app and test each schedule with time set to now to prove it works ok.

Dave
thanks for that. I tried the v2 interface as you suggested and no success. Have tried "disable" for the Mode Schedule and then "Force Time Change" is active (so the batteries will charge). Still no movement from the batteries.

Is there a "factory reset" one can perform on the inverter to get to a clean slate? Or something similar on the App?

jverdicchio wrote: ↑Mon Jan 05, 2026 1:02 pm Still no movement from the batteries.

Can you grab your BMS Cell Temp Low value as seen in this post?
viewtopic.php?p=11800#p11800

I've looked through the App and website (both old and new versions) and the documentation for the API and can find no mention of BMS.
I looked at the post and saw that people had recorded that BMS temperature but didn't say how they had done it.

According to the App:
Min. Battery Temperature -3.5C

Ah! Found I can get some more data via the API and path = '/op/v0/device/real/query' call.
I get:
{
"unit": "℃",
"name": "AmbientTemperature",
"variable": "ambientTemperation",
"value": 10.5
},
{
"unit": "℃",
"name": "InvTemperation",
"variable": "invTemperation",
"value": 0.1
},
{
"unit": "℃",
"name": "batTemperature",
"variable": "batTemperature",
"value": 6.1
},
It's currently -5C outside - which is where the batteries and inverter are.
I was told that my battery pack was heated, they are the EP12. From what the forum says, that doesn't seem to mean too much though.

jverdicchio wrote: ↑Mon Jan 05, 2026 9:58 pm I've looked through the App and website (both old and new versions) and the documentation for the API and can find no mention of BMS.
I looked at the post and saw that people had recorded that BMS temperature but didn't say how they had done it.

According to the App:
Min. Battery Temperature -3.5C

I was told that my battery pack was heated, they are the EP12. From what the forum says, that doesn't seem to mean too much though.

Well that cold and you will have big troubles.
Are your batteries stored in garage/house/outside?
Can you find your firmware of your batteries?

ETA: I might also be a numpty in thinking you are using some kind of Home Assistant, mentioning API queries might have led me down the wrong path.

I run Loxone in my house but that isn't talking to the batteries at the moment. I'm doing all the API queries with some python scripts.
Attached to the outside of the house on a north facing wall. Battery and inverter exposed to the cold Derbyshire air.
"batteryList": [
{
"batterySN": "60EP612057CQ054",
"model": "EP12",
"type": "bcu",
"version": "1.007"
},
{
"batterySN": "60EP612057CQ054",
"model": "EP12",
"type": "bmu",
"version": "1.07",
"capacity": 11520
},
{
"batterySN": "60EP612057CQ056",
"model": "EP12",
"type": "bmu",
"version": "1.07",
"capacity": 11520
},
{
"batterySN": "60EP612057CQ054",
"model": "EP12",
"type": "ivu",
"version": "0.00"
}

jverdicchio wrote: ↑Mon Jan 05, 2026 10:36 pm I run Loxone in my house but that isn't talking to the batteries at the moment. I'm doing all the API queries with some python scripts.
Attached to the outside of the house on a north facing wall. Battery and inverter exposed to the cold Derbyshire air.
"batteryList": [
{
"batterySN": "60EP612057CQ054",
"model": "EP12",
"type": "bcu",
"version": "1.007"
},

Ok, some kind of Home Assistant eco system, looks fancy.

You probably are realistically going to need to build a shelter for the batteries, or they will struggle with the heating.
Plenty of threads/ideas on here about doing this safely (ventilation for Spring->Autumn)

Your EP12's will most likely need FW upgrade doing ASAP in order to unlock working heating.
It seems version 1.009 is needed minimum for it to "engage" current firmware is v1.011.

You might also need a firmware upgrade to your inverter at the same time, as this can also cause issues in even seeing heated batteries as a choice.

Your Fox Cloud 2.0 App on your phone and tablet is the way to check your Cell Low temp for now, and you can also check your Quick Settings to see if you have heater controls greyed out, or as a possible selection (if you cannot see heater controls, press edit on right to check)

MaterialBarracuda48
Thank you very much. What do you know, I looked at the "quick settings", noted your comment about "edit" and there is a "Battery warmup" entry. And, it's greyed out.

I'm guessing that Fox are the only people that can do the FW upgrade? Contact the UK office by phone?

Once again, thanks very much for the help.

jverdicchio wrote: ↑Mon Jan 05, 2026 11:24 pm MaterialBarracuda48
Thank you very much. What do you know, I looked at the "quick settings", noted your comment about "edit" and there is a "Battery warmup" entry. And, it's greyed out.

I'm guessing that Fox are the only people that can do the FW upgrade? Contact the UK office by phone?

Once again, thanks very much for the help.

Mine was greyed out, until I had FW upgrade done on Inverter.
Next the battery FW for mine was 1.005 and though heater controls now appeared, they didn't work at all.
I had -40C starting point to a possible +50C! Once FW was upgraded to 1.009, the heater worked.

So you might need two steps.
I would fire off an email service.uk@fox-ess.com tonight, Subject Battery heater controls
Include your Inverter serial number in first line

Then add some fluff about having no heater controls etc available.


If for some reason your EP12's have no heating elements, then you may need that shelter building ASAP.
My EP11 has a nice WARM sticker slapped on the side, I presume EP12's get the same label system.

Either way, a FW upgrade won't hurt as there are bugs with the older versions.

Hats off to Fox support. They've answered my email, pushed the Firmware updates to my batteries - hurrah! I have a warm battery and it is now supplying power to my house again. They even sent through some documentation about how to use the new features.

jverdicchio wrote: ↑Tue Jan 06, 2026 2:13 pm Hats off to Fox support. They've answered my email, pushed the Firmware updates to my batteries - hurrah! I have a warm battery and it is now supplying power to my house again. They even sent through some documentation about how to use the new features.

Glad you got supported so quickly, they did half the job I asked for today... upgraded my Inverter FW, but left my battery on v1.009 that is sitting at 6C. I might need to fire off 2nd email to ask again for battery upgrade

I spoke too soon.
I woke up this morning to check on the state of the batteries. Oh dear, sat at 10% and they had not charged overnight. The heating is on so that can't be the problem. I have checked the firmware on the inverter - that is up-to-date.

jverdicchio wrote: ↑Wed Jan 07, 2026 9:10 am I spoke too soon.
I woke up this morning to check on the state of the batteries. Oh dear, sat at 10% and they had not charged overnight. The heating is on so that can't be the problem. I have checked the firmware on the inverter - that is up-to-date.

That's sad to hear.

What method are you using to charge up your batteries now, Fox Cloud 2.0 App / Website v1 / Website v2 / Loxone

I set up via the "Quick settings", the "Grid Charging Times" via the web V2 interface. That does seem to be consistent between the App and the web interface.

I noticed that even though the grid charging appeared to be "on" (button to the right) with the times set, the message next to the display said "Charge from grid disabled". Going into the setup again and typing the exact same numbers and again setting the "on" button then resulted in "Charge from grid enabled" to be displayed.

I am now going to eat my words - I was about to type that the battery wasn't charging. Having changed the settings and waited a couple of minutes whilst I type this message, the battery is now charging!

The Fox Cloud is always slow to react, you probably would have seen in on inverter screen minutes before the App/website noticed. I think once you have the scheduler working as intended you are going to be fine.

Fingers and toes all crossed.

jverdicchio wrote: ↑Wed Jan 07, 2026 11:06 am
I noticed that even though the grid charging appeared to be "on" (button to the right) with the times set, the message next to the display said "Charge from grid disabled". Going into the setup again and typing the exact same numbers and again setting the "on" button then resulted in "Charge from grid enabled" to be displayed.

The app is also very poor at refreshing previous screens, whenever you change something in schedules it is best to either force a refresh by pulling down on the home screen or force close the app and launch it again.