Re: Fox EVO 10-8-H modbus registers
MattyS wrote: Fri Apr 10, 2026 6:51 pm Some of the registers throwing errors are ones I assume should be working regardless.

Interestingly, the integration seems to think I have a 10kWh inverter. I have a 5kWh. Maybe that's a clue
Ok so my installers HAVE given me a 10kWh inverter version, how nice of them.

I stood there with the installer and we worked together to double and triple check what wire would go where. I'm going to look at the modbus register PDF to see if I can find out whats going on because the integration is suggesting that work mode changing isn't available on my system which is clearly wrong.

tcp://192.168.1.136:502 247: register 41003 is invalid
tcp://192.168.1.136:502 247: register 41004 is invalid
tcp://192.168.1.136:502 247: register 41005 is invalid
tcp://192.168.1.136:502 247: register 41006 is invalid
tcp://192.168.1.136:502 247: register 49203 is invalid
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
MattyS wrote: Fri Apr 10, 2026 8:10 pm
MattyS wrote: Fri Apr 10, 2026 6:51 pm Some of the registers throwing errors are ones I assume should be working regardless.

Interestingly, the integration seems to think I have a 10kWh inverter. I have a 5kWh. Maybe that's a clue
Ok so my installers HAVE given me a 10kWh inverter version, how nice of them.

I stood there with the installer and we worked together to double and triple check what wire would go where. I'm going to look at the modbus register PDF to see if I can find out whats going on because the integration is suggesting that work mode changing isn't available on my system which is clearly wrong.

tcp://192.168.1.136:502 247: register 41003 is invalid
tcp://192.168.1.136:502 247: register 41004 is invalid
tcp://192.168.1.136:502 247: register 41005 is invalid
tcp://192.168.1.136:502 247: register 41006 is invalid
tcp://192.168.1.136:502 247: register 49203 is invalid
I checked those registers all of mine are invalid except 49203 which returns “1”.
Re: Fox EVO 10-8-H modbus registers
Any firmware updates available for the unit?
I remember they had to update my firmware from the install.
Re: Fox EVO 10-8-H modbus registers
AdamNewberry wrote: Fri Apr 10, 2026 9:08 pm Any firmware updates available for the unit?
I remember they had to update my firmware from the install.
my installer did do a couple of installs, but it appears there are much more recent versions. I'll be speaking to my installer.

here are the versions from my foxcloud:

Version_Master:
9.42
Version_Slave:
1.00
Version_Manager:
1.01
Version_BCU:
1.001

the latest as per Wills spreadsheet are :

Master 1.15
Slave 1.00
Manager 1.10
BCU (Master) 1.04

not sure why the master versions are vastly different.
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
BOD wrote: Fri Apr 10, 2026 9:00 pm
MattyS wrote: Fri Apr 10, 2026 8:10 pm
MattyS wrote: Fri Apr 10, 2026 6:51 pm Some of the registers throwing errors are ones I assume should be working regardless.

Interestingly, the integration seems to think I have a 10kWh inverter. I have a 5kWh. Maybe that's a clue
Ok so my installers HAVE given me a 10kWh inverter version, how nice of them.

I stood there with the installer and we worked together to double and triple check what wire would go where. I'm going to look at the modbus register PDF to see if I can find out whats going on because the integration is suggesting that work mode changing isn't available on my system which is clearly wrong.

tcp://192.168.1.136:502 247: register 41003 is invalid
tcp://192.168.1.136:502 247: register 41004 is invalid
tcp://192.168.1.136:502 247: register 41005 is invalid
tcp://192.168.1.136:502 247: register 41006 is invalid
tcp://192.168.1.136:502 247: register 49203 is invalid
I checked those registers all of mine are invalid except 49203 which returns “1”.
49203 is work mode I believe.

by the way everyone, I've taken the liberty of indexing the Evo github on deepwiki here: https://deepwiki.com/AdamNewberry/foxess_modbus_EVO

it has an AI that you can ask questions about the code etc. Despite my issues with AI in general it may be quite useful.
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
I forgot who told me, maybe it was even fox, but I understood that 9.x firmwares are development, typically ship with a factory unit and must be updated.Fox allow you to update firmware via the fox cloud app yourself now. Go to the device tab the click the device icon. It should show you what upgrades are available.
Re: Fox EVO 10-8-H modbus registers
AdamNewberry wrote: Sat Apr 11, 2026 7:09 am I forgot who told me, maybe it was even fox, but I understood that 9.x firmwares are development, typically ship with a factory unit and must be updated.Fox allow you to update firmware via the fox cloud app yourself now. Go to the device tab the click the device icon. It should show you what upgrades are available.
I've just checked and that option is not there. on the device screen it doesn't say any updates are available
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
On the iOS app?
Re: Fox EVO 10-8-H modbus registers
May be worth firing an email off to fox. They were pretty quick to update mine via support ticket before the self
Update feature came.
Re: Fox EVO 10-8-H modbus registers
AdamNewberry wrote: Sat Apr 11, 2026 8:01 am May be worth firing an email off to fox. They were pretty quick to update mine via support ticket before the self
Update feature came.
I'm on Android. and that is the exact page I'm looking at . no updates, no bubble, no red dot.

I've messaged my installer.
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
Sorry can’t be of more help. I hope (and suspect) the firmware update will fix it! I couldn’t get the integration going until I got firmwares updated.
Re: Fox EVO 10-8-H modbus registers
AdamNewberry wrote: Sat Apr 11, 2026 8:06 am Sorry can’t be of more help. I hope (and suspect) the firmware update will fix it! I couldn’t get the integration going until I got firmwares updated.
No need to apologise, your advice and integration is of great help to me :) Thanks!
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
Modbus all up and running now. Firmware update did the trick. Still need more though. Will speak to Fox 🤣🤣
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
Glad it’s sorted and working.
Re: Fox EVO 10-8-H modbus registers
Hi there Adam/all,

I'm trying to understand modbus a bit more and how to adjust/ add sensors into my home assistant without borking your great work.

I've seen that register 37611 "ambient temperature" isn't being populated by my system, it's showing as 0°C.

Also I'm trying to find a way of reading and writing to the battery warm up function which is at register 53400 to 53415 ( for a 2 BMS system)

Would you know if this is possible?

Edit: just found the actions feature in HA, and I can see that ambient temperature should be possible to get, but it's gain 10 which I assume means value x10.

The warming feature appears to be accurately showing as on, with start and end temperature reporting as per how my installer has set.

Interesting.
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
We're back on for our install, now booked in for 27th April. Seems my installer put some pressure on NG and they have come back allowing the install with the inverter set to export 3.68kW. They're also in the process of upgrading our LV connection but, that will likely take a while to complete. But, I'd hope we can then export at the full capacity the inverter will support.
As I had the opportunity, I thought I should maximise the array. So I've gone for the 495w Aiko panels (from 475w) and from 14 to 18 panels, as we have a west facing aspect of the roof that could take the 4 extra panels. For the extra up front cost for another 1/3rd peak output, was really a no brainer.

This now means that I need to go back a re-read the entire thread in case I've forgotten or missed anything. :D

Paul
8.94kW Array. 18 x Aiko Neostar 3S 495W panels. 14 S, 4 W facing. Fox ESS Evo 10, 10kWh storage with 10kW inverter. Fox ESS EPS 1PH Backup. Installation planned for 27th April 2026. Will be running ModBus via Elfin EW11a through Home Assistant.
Re: Fox EVO 10-8-H modbus registers
youngsyp wrote: Wed Apr 15, 2026 2:52 pm We're back on for our install, now booked in for 27th April. Seems my installer put some pressure on NG and they have come back allowing the install with the inverter set to export 3.68kW. They're also in the process of upgrading our LV connection but, that will likely take a while to complete. But, I'd hope we can then export at the full capacity the inverter will support.
As I had the opportunity, I thought I should maximise the array. So I've gone for the 495w Aiko panels (from 475w) and from 14 to 18 panels, as we have a west facing aspect of the roof that could take the 4 extra panels. For the extra up front cost for another 1/3rd peak output, was really a no brainer.

This now means that I need to go back a re-read the entire thread in case I've forgotten or missed anything. :D

Paul
Nice! Extra panels is ALWAYS worthwhile. My installer gave me an extra panel for free because it'd fit.
Hope your installation goes well.
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
MattyS wrote: Wed Apr 15, 2026 3:51 pm
youngsyp wrote: Wed Apr 15, 2026 2:52 pm We're back on for our install, now booked in for 27th April. Seems my installer put some pressure on NG and they have come back allowing the install with the inverter set to export 3.68kW. They're also in the process of upgrading our LV connection but, that will likely take a while to complete. But, I'd hope we can then export at the full capacity the inverter will support.
As I had the opportunity, I thought I should maximise the array. So I've gone for the 495w Aiko panels (from 475w) and from 14 to 18 panels, as we have a west facing aspect of the roof that could take the 4 extra panels. For the extra up front cost for another 1/3rd peak output, was really a no brainer.

This now means that I need to go back a re-read the entire thread in case I've forgotten or missed anything. :D

Paul
Nice! Extra panels is ALWAYS worthwhile. My installer gave me an extra panel for free because it'd fit.
Hope your installation goes well.
Thank you re the install wishes. Me too!

I really like your signature. I think having that, on a board like this is insightful. I'll follow suit.

Paul
8.94kW Array. 18 x Aiko Neostar 3S 495W panels. 14 S, 4 W facing. Fox ESS Evo 10, 10kWh storage with 10kW inverter. Fox ESS EPS 1PH Backup. Installation planned for 27th April 2026. Will be running ModBus via Elfin EW11a through Home Assistant.
Re: Fox EVO 10-8-H modbus registers
I've just created a fork of the Evo modbus GitHub to see if I can get battery warming and ambient temperature to work. I'm not a dev by any stretch but I know a tiny bit about yaml and I'll be scanning the modbus documentation and existing files to see where I can shoehorn the Evo in 😁
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
Re: Fox EVO 10-8-H modbus registers
It looks like "ambient temperature" is actually referring to "battery temperature" and I've got that working along with battery state of health. I'll now be working on getting battery warming sorted out, but it's more complicated because it uses high and low byte register values.

Happy to provide the code updates Adam if that's helpful.
7.34kWh solar array made of 16x Jinko Tiger Neo 460w panels. 8 ESE, 8 WNW facing, Fox EVO 10kWh with 10kW inverter. Installed April 2026. Running ModBus via Elfin EW11A, learning Home Assistant
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