New installation H1 6G2 + EP11 version Master 1.22 comunication problems
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
User avatar
Site Admin
Re: New installation H1 6G2 + EP11 version Master 1.22 comunication problems
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.
Community Admin / FoxESS Elite Professional

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Re: New installation H1 6G2 + EP11 version Master 1.22 comunication problems
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
Re: New installation H1 6G2 + EP11 version Master 1.22 comunication problems
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?
Re: New installation H1 6G2 + EP11 version Master 1.22 comunication problems
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.
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