FoxESS Community - Owners & Installers Forum

Before I get onto Fox, I'm hoping that there is an easy fix someone knows about.

Two days ago I switched from Self Use to Feed-In Priority, as I normally do at this time of year, after which my battery went into Online Standby Mode.

While it still discharges normally and charges from the grid overnight, it won't charge from solar. As soon as the sun goes down it continues to discharge until it charges from the grid between 2.00 and 5.00am.

When I switch back to Self-Use, it immediately starts charging from solar.

This is a brand new development (for me), as I always used Feed-In Priority during the spring/summer, and have never experienced this before.

Normally, when I use Feed-In I see a greater percentage being exported to the grid, but the battery is still being charged from solar, albeit at a lesser percentage. Now, it won't charge from solar at all unless I put it back into Self Use.

Any ideas?

Thanks.

Feed-in shouldn't normally charge the battery, never has*

PV->Load->Export->Battery*

The Battery only charges in this mode if your export limit is breached.
Example 6kW of PV generation, 1kW house load and a 4kW export limits gives a spare 1kW. The spare 1kW will be mopped up by the battery if there is capacity spare (less than 100% SoC)

Feed-in mode in action,
Export limit is 3.9kW
PV is 4.42kW
Load is 0.29kW
The spare goes to the battery as 0.23kW of charging
Later in the year, you are going to see more battery charging once you breach your export limit, as will I also.

Thank you so much for the detailed (and easy to understand) reply. I feel a bit of a twit now, but I've honestly never noticed this behaviour when I've been using Feed-In, and when my battery suddenly 'flatlined' at peak solar production and would not charge, I thought something was amiss. (See screenshot below]

Thanks for explaining what's going on. I've learnt something new today!

That's ok Gary, definitely don't feel a twit about it.
At least you know that you have to go beyond your Export and Load to charge the battery.

I think if you go back to Summer last year, you will see battery charging going on during a decent day.