FoxESS Community - Owners & Installers Forum

Hi,
i am owning a new system, equipped with inverter and battery. While the inverter works in general, feeding in solar power to the grid, my battery fails with bms lost message. In addition the inverter shows a battery voltage of 0v and battery switches itself off after a while, as communication seems to be faulty. the bms cable, a rj45 cable is ok, it is a rather short connection and using a rj45 cable tester, all contacts are fine. I am wondering if the battery voltage connection itself is faulty?
How do i properly disconnect it for a check(after powering down the whole system)
Any ideas? Currently my dealer, who also installed the system, is not reacting at all
Thank you
Kind regards,
Paynie

It sounds like a flaky comms cable between the inverter and BMS (i've seen quite a few of these); If the inverter and BMS cannot reliably communicate, the BMS opens it's contactor and disconnects the battery (hence you seeing 0V).

Obviously make sure that you have latest firmware on the inverter and batteries, but i'd start by powering off the batteries, open the DC isolator switch - then replace the inverter to BMS cable with a new one.

Hi Dave,
thanks a lot for your fast answer.
I exchanged the cable and performed a complete system restart, but with no success.
After restart i realized the blink codes on the EQ5000 battery.
For a couple of minutes the BMS LED blinked green 0.5s on/off, which is according to manual bootup.
During boot up phase the SOC LEDs signal a SoC between 25% and 50%.

Afterwards it changed to BMS blinking red with the four SOC leds being solid green.
According to manual this means PCS communication failed.

At the same time the inverter did already start to display BMS lost with a blinking red LED.

From the cloud app i can see the used versions:
FW Version Master 1.44
FW Version Slave 1.0
FW Version Arm 1.26

It also throws error 14 - communication fault between device and battery in the dashboard.

Is there anything else, what i can check?

The battery did not yet work at any time.

Kind regards,
Paynie