Battery continues to export to grid despite being set to Self Mode

[bens00n]

Hi everyone,

I’m looking for some advice and support with an ongoing issue we’re seeing with our FoxESS battery system, which doesn’t appear to be operating as intended.

Issue summary
Despite being configured in Self Mode, the battery is:

Not retaining charge, and

Consistently exporting stored energy back to the grid, even when household load is very low.

This behaviour is persistent and repeatable.

What I’ve tested so far
The installer initially suggested the issue may be related to the hot water system. To validate this, I’ve:

Run the system with the hot water system completely switched off

Tested across multiple days with minimal household usage

The issue continues to persist unchanged.

PowerBills data also indicates that the system is significantly over-estimating household load, which appears to cause:

Solar charging to stop prematurely during the day, and

Stored battery energy to be exported in the evening instead of supplying the home.

Example
On Friday 2 January, the battery reached full charge while we were away and household usage was minimal. Despite this, the battery continued exporting energy back to the grid for ~18 hours until fully depleted — all while still set to Self Mode.

Additional complication
The installer has configured the system in a way that currently prevents the supplier from logging in remotely to diagnose the issue. Any guidance on restoring supplier access (or how to remove installer restrictions) would be greatly appreciated, as this seems necessary for proper troubleshooting.

My working assumption
Based on the testing above, this feels more like a unit-level configuration, firmware, or hardware issue, rather than a household load problem.

Looking for guidance on:

How to restore remote access for diagnostics

Whether a configuration or firmware review is recommended

Whether this could indicate a faulty unit requiring repair or warranty replacement

I’m happy to share logs, screenshots, PowerBills data, or system details if helpful.

Thanks in advance to anyone who’s experienced something similar or can point me in the right direction.

[MaterialBarracuda48]

That's a fair bit to unpack, starting with the basics...

Do you have access to the Fox Cloud 2.0 App to view your system settings/values?

[nrb501]

Charging then dumping battery to grid sounds like the current transformer may be fitted incorrectly (wrong way round)

[MaterialBarracuda48]

Charging then dumping battery to grid sounds like the current transformer may be fitted incorrectly (wrong way round)

I was thinking same earlier, but would be nice to find out what they can/cannot see to get some evidence hopefully.

[bens00n]

Yes, Im running version 2.1.86 of the app, which I believe is the latest..

I turned my hot water system off overnight again, and that appears to have made a difference, as I scheduled a charge from grid, and the battery appears to have retained the charge, its still currently at 97% at the time of writing where normally it would be approx 40-50% by this stage with the hot water system on.

[MaterialBarracuda48]

As you have the Fox Cloud 2.0 app, you can show a few screenshots of information that could assist.

Main page, Quick Settings a screenshot to get an overview.
If your mode scheduler is enabled, for example Manual Scheduler, you can take screenshot of those.

You can then swipe screen right to left, that gives solar/grid usage... scroll down to bottom and if you expand the energy graph... a screenshot of today, and a previous day where battery was drained.


It could be your water heater is using a fair bit of power, those graphs will show this clearly.