Feed-in-first mode still using approx 250w to top up the battery

[foxesstico24]

Hi all.

I had my system installed about a week ago and since then I have spotted a slightly confusing issue. When the inverter is in "feed-in-first" mode and the PVs are producing more than the house is using, approximately 250w goes into the battery rater than to the grid.

This means that a a battery on about 80% at the start of the day will be full before the end of the day. This is not the most cost effective use of PV energy for my setup.

I can work around this issue by setting the max SoC to a low number during the day, and then all the excess power goes to the grid as expected, but this is not ideal. I would like to be able to set the SoC to a high % and have all excess power go to the grid when I am on feed-in-first mode.

My installer struggled in the arses-and-elbows department so I am not confident that they would know the answer to this, so I thought I would ask here.

My setup is slightly unusual in that I have microinverters, so all the PV is routed to the AC side of the inverter and the string side of the inverter is not used. Fox did confirm (a number of times!) that this setup is fine, and that the inverter will work as expected. Aside from this issue, it does seem to be working as expected.

I have modbus access to the inverter and I have agent access (because my installer was terrible so I grabbed it for myself) so I can change settings if needed. Any advice would be appreciated.

Hardware:
- KH8 inverter.
- 20kW of ECS battery storage.
- 6ish kw of PV through microinverters.

Firmware:
- Manager: 1.40
- Master: 1.41
- Slave: 1.01