FoxESS Community - Owners & Installers Forum

Hi all,

I got a FoxESS H1 6kW with an EP11 battery in Portugal and running into issues.

Setup:

• H1-6.0-E-G2 wifi inverter + EP11 battery (single unit)

• Grid not yet connected (testing with alternative power supply)

• PV DC switch OFF during tests, and during night

Symptoms

• Inverter boots, shows "Waiting…", no errors initially.

• When starting the EP11, SOC shows (49%) in the inverter, then in the battery the “S” LED on the battery flashes red and SOC right led becomesfixed green.

• Inverter shows error (normal I think) "Grid Lost Fault", "Waiting…", and blinking “Play” LED blue, “!” LED red.

Checked

• Using original PCS cable (BMS → PCS).

• Startup order tested both ways.

• Firmware versions: Master 1.22 / Slave 1.02 / ARM 1.37.

Questions

• Is this a firmware issue (H1 v1.22 too old for EP11)?

• Does the unused PCS port need a termination plug?

• Is “Grid Lost Fault” simply because I’m not on the real utility grid? (It only apears with better start)

• What is the expected LED behavior when EP11 ↔ H1 communication is OK?

Thanks for your help!
Regards from a curious guy

Did you install the bypass plugs into the EP11 battery. they're required when you're running a single EP battery and is a common mistake.

Thanks, I will confirm that with the installer personal, but I'm suspicious that was installed, because it have the 2 terminal plugs. The team that went there was new, and was more used to install other brands, for 2 members was the first time with FOX.

The battery error is according to the manual "Parallel addressing failure ■ ● / / "

How can I check that in advance?
thanks in advance

Will wrote: ↑Tue Sep 30, 2025 9:01 pm Did you install the bypass plugs into the EP11 battery. they're required when you're running a single EP battery and is a common mistake.

Thanks solved.

There is missing information regarding battery health and remaining charge in the app 2.0. could this be a firmware issue?

toze3 wrote: ↑Thu Oct 02, 2025 6:46 am

Will wrote: ↑Tue Sep 30, 2025 9:01 pm Did you install the bypass plugs into the EP11 battery. they're required when you're running a single EP battery and is a common mistake.

Thanks solved.

There is missing information regarding battery health and remaining charge in the app 2.0. could this be a firmware issue?

It’s possible but not all battery types have all of that information, that said I would expect the EP to provide this and your firmware is quite old - don’t forget to update Master, Slave, ARM and your battery firmware to the latest.