FoxESS Community - Owners & Installers Forum

Hi all,

As the temp is dropping and I am noticing slower charging overnight, I was considering insulating the battery, that is in the garage.
Obviously I want to monitor the temperature, but I'm a little confused over the temps from the apps and website.

On the phone app, as I was looking at turning on the 'warming' feature, last night it was showing the battery was 10'C, but on the website 'batTemperature' was showing 22.9'C
This morning the battery in the phone app is 16.9'C and the website is 27.4'C

Seems quite a big delta?!

The website is saying all is good, nice and toasty, but the battery is ramping up charging in stages when charging overnight, so its obviously more likely to be what the phone app is reporting.

The website and energy stats app use the BMS temp, which is the internal battery management chip at the top of the battery. Normally, 10-12°C higher than the true battery cell temps. On the foxcloud2 app under devices battery, that temp is showing you the lowest cell temps, which is the measurement used to control the bms charge and discharge rate.

Thanks Will!

Don't suppose you know what wattage the heater element if for the EP-11 battery?
Insulation board seems quite pricey and struggling to find anyone with some left overs.
Wondering if its low wattage, if its going to cost that much to warm it, in the cheap period.

ah, found you state in another thread, around 200w

@Will


Sorry to labour a point.

On the app when you see the graphic of the battery in the Battery warmup option, is the temperature shown the lowest cell temp as discussed above, and it’s this temp that controls when heating kicks in and out ?

Thanks

Like other people seeing battery temps drop this week .. so I had enabled the Battery Warm function ... but for some reason, even though it says that the battery is heating (presume the arrows are showing this) .... the BMS temp is dropping and no discharge happening from the battery .. even though battery on 100% .. not sure what is wrong here

How can you track the BMS temp without HA?
I cant see it on any graph.

Device
Inverter
Analysis Graph
Expand icon
Filter icon
batTemperature
Submit

The app software is buggy, was playing around with battery warmup temp yesterday, and after changing start temp to higher value, the app then greyed out ‘Battery warmup’ option.
Had to log out and in, only to realise it takes a 5 min cycle to display correctly.
Also the inverter switched to grid supply only for several minutes after each change, before it settled down and started supplying battery power to load.
Unwanted side effect was only seen last night, when battery started to force discharge.
On investigation the schedules I had set in mode scheduler, 1 was active, 3 were disabled had all gone active.
The time segments remained as set but where I had set lower FD Power settings, they had all set to 6000w !
This is after weeks of nightly force charge being set to 4000w and operating correctly.

CDubbs wrote: ↑Thu Nov 20, 2025 8:29 am Device
Inverter
Analysis Graph
Expand icon
Filter icon
batTemperature
Submit

But 'batTemperature' is the chip on top, not the lowest temp the BMS sees. I can only see the temp I'm interested in, in the phone app, if I am awake to see the temp rise (which I am not lol)

Any temp rise on 'batTemperature' I have to see if it aligns with something else, dish washer...washing machine...which made its temp rise.
I cant see a way to categorically see its the warming feature that's warmed it.

Misunderstanding that I thought you were referring to the chip, but think you mean the reported temp of the coldest cell.
If that’s what you wanted, add me to the queue.

TBH this weeks been an eye opener for me and a couple of friends, we all had solar installs in Sep & Oct 25, same panels, and batteries just different rated inverter, mines 6k theirs are the 3.7k versions.

I’ve seen inconsistent behaviour on battery warming and scheduling options. They have seen identical issues.
I’ve had warming not coming in when set to 8C and battery level above 75%, and battery not supplying any load and battery temp drifting down to 4C, only after switching off battery warming did the battery start supporting house load, then re-enabling warming, suddenly the battery started warming and quickly reached 12C even though cut off was 10C.
Whilst warming, the battery supplied all house load and did not draw from the grid.

In an attempt to keep battery activity running during coldest night hours, set draw from grid power to 2500W, so it would keep cells charging, this was completely ignored by the inverter which charged at 4K then 6K.

IMO the software and/or inverter functionality are at best variable, it’s hard to see if it’s a hardware issue, or software issue, that states it’s accepted your parameters but hasn’t actually coded them into the inverter.

My friends are seeing the same issues, and I wonder how many other users are seeing similar issues.

After discussing the issues with my installer, they agree there are issues Fox need to improve and just call the issues a ‘minefield’, wish I could have got away with telling that to my clients when their secure financial voice lines went down

Unfortunately the poor state of documentation, actually lack of meaningful documentation does not help the situation.
Overall the Fox kit seems passable, as in it supplies voltage to load and charges and stores energy in a battery, export excess to grid, but most of the peripheral items around currently seem to lack development, and need some improving.
I’d give it a 6 out of 10 at present, there’s something good in there, just needs some urgent TLC to improve it to a level of consistency I would have hoped to have seen out of the box.

H1/AC1 6k G2
1 x EP11 heated
16 x JA 450w panels.