EP11 with heater

[WyndStryke]

However, the fox ess cloud data is showing the battery temperature as much hotter (which doesn't make much sense as it's 6c outside).

There are actually a variety of different battery temperatures, I suspect the high one is the BMS battery temperature, which is the temperature inside the BMS. This will be noticeably higher than the 'BMS cell temperature low' reading, which is the temperature of the coldest cell. The 'BMS cell temperature low' is the important one as far as the battery heating system is concerned.

Regarding time zone, mine was OK so I've never looked into it, but google suggests that it can be set via the website's plant information screen. Not sure if it is a user level setting or an installer setting.

[Arwith]

@Arwith Can you tell me when you put in your support ticket please?
I put one in on the morning of the 20th, and it just sits at processing.

I emailed them on the 20th (service.uk@fox-ess.com), my first response was on the 21st asking for the inverter SN, and then the next response confirming they updated things was on the 24th

[MaterialBarracuda48]

@Arwith Can you tell me when you put in your support ticket please?
I put one in on the morning of the 20th, and it just sits at processing.

I emailed them on the 20th (service.uk@fox-ess.com), my first response was on the 21st asking for the inverter SN, and then the next response confirming they updated things was on the 24th

Thank you for the update, so my ticket is perhaps stuck.
I went via the app initially, and sent a chase email last night.

[Arwith]

Regarding time zone, mine was OK so I've never looked into it, but google suggests that it can be set via the website's plant information screen. Not sure if it is a user level setting or an installer setting.

Time zone on the website at least seems correct (though the postcode was wrong, I remember when setting up I could only use numbers on the app...)

Screenshot 2025-11-25 113312.png (1.92 KiB) Viewed 394 times

Hopefully it's not something the installer would have to do as mine didn't really know how to set it up, i set up the app myself in the end, though there appears to be not setting in the app for timezone, just country which is set correctly, just weird

[Arwith]

@Arwith Can you tell me when you put in your support ticket please?
I put one in on the morning of the 20th, and it just sits at processing.

I emailed them on the 20th (service.uk@fox-ess.com), my first response was on the 21st asking for the inverter SN, and then the next response confirming they updated things was on the 24th

Thank you for the update, so my ticket is perhaps stuck.
I went via the app initially, and sent a chase email last night.

Seems the turnaround for email is about 1 working day so hopefully they can help you out there

[MaterialBarracuda48]

Seems the turnaround for email is about 1 working day so hopefully they can help you out there

Thanks, let's hope I get a nice quick turnaround.

[doubl0dave]

In addition to this blocking of charging, I've noticed inconsistencies between the reporting from fox ess cloud and the app. Currently my battery temperature in the app is saying the batteries are 6c, the warmup feature is on and it's climbing by 0.1 every 5 minutes or so so hopefully it is actually heating. However, the fox ess cloud data is showing the battery temperature as much hotter (which doesn't make much sense as it's 6c outside). The app is most likely correct, just odd that there would be different reporting

Screenshot 2025-11-25 110948.png

App temperature is lowest cell temperature which the online version does not show. battemp is actually BMS temperature, not lowest cell. This is the critical temperature for the battery and determines charge characteristics I believe.

[iew100]

I've been upgraded to 1.52 master on KH7 and battery BMS firmware 1.009 on my two EP11s. So far, the heater has started every time the lowest cell temperature has reached the 9C trigger point. That has only been during the daytime though. I've set the possible charge from grid option to be anytime in the 24 hour window, though the heater power draw has always been from battery so far. I'm hoping this is a consistent and reliable firmware implementation now.

[Arwith]

everything now working for me, did have to contact support again as it seemed the force charging stopped working, but they pointed out that the default setting in the mode scheduler called "force discharge pwr" was 100W and upon increasing it to 8000w (the size of my system) immediately my charging started working so hopefully all my settings are correct now

[MaterialBarracuda48]

I now have the 1.009 BMS firmware, so hopefully I can get it to warm up now.
My battery temperature sliders are now also "correct" and no longer -40C to + 50C

My original ticket was lost, so just as well I chased it up yesterday, thanks to those that have provided information.

ETA: Small video captured to show heater in action for those curious. Grid heater set from 00:30 to 05:29, so this was charging from either solar or self-use this morning.

Battery Heater.zip

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