On-grid domestic battery storage

Qyburn

The 2012 system remains separate and as installed, but the hybrid inverter 'sees' the export, when that system exceeds household consumption, and uses it to charge the batts, alongside any PV generation from that side too

Thinking this through I can't see that behaviour specifically documented, nor a setting to control it. I don't have a separate system to check, so can only make a guess. My guess is that it's inherent in the default mode "Maximise Self Consumption". In that mode my system tries to maintain import/export at zero by varying inverter output, with surplus solar going to the battery. The behaviour you see suggests it goes further, dropping inverter output below zero and charging from AC if needed.

It would be interesting to see if that AC Charge Policy affects this bebehaviour.

Martyn1981

https://forums.moneysavingexpert.com/discussion/comment/82062356#Comment_82062356

Many thanks. Sorry for the delay, had to get the Alpha Geek on it (wifey). Even then we managed to confuse ourselves.

Just tested and it seems to work perfectly. Our 'other' system was generating a healthy 1.3kW. So I told the battery system to stop exporting, and the energy monitor slowly dropped to zero. Whilst the app showed ~1kW being exported, and crucially, not being grabbed by the battery system.

I set the AC charge limit to zero kWh. When it comes time to charge from the grid, on cheap rate, maybe Oct/Nov, I'll change it from kWh to % and set it for 80% or 90%. Solaredge say 100% is fine, but I don't need it all now, so maybe a buffer would be best.