Timed Export

I have 18kw of battery storage and a gen 3 5kw inverter, I am currently signed up to Octopus Flux.
I charge the battery during the night but if it is cloudy the battery will not reach 100% at any point during the day.
Question is I have the timed export set to 4pm-7pm, with the battery set to discharge to 30%; if the battery is able to discharge for the full 3 hours I have no issues, if the battery is only say at 60% it can only discharge for approx 1.5 hours before it is down to 30%.
Issue is when it has discharged instead of using the the 30% battery storage still available to power the house it draws from the grid until 7pm, at that point it then reverts back to drawing power from the battery.
Any help/advise would be greatly appreciated ?

Thanks Paul

Don't discharge to a set limit, start the discharge at the most appropriate time to reach the limit around 19:00.

I presume you are on Octopus Flux?

https://givenergymonitor.wixsite.com/tutorials/tariffs#flux

Paulbooth As @Rubikcube says, this is the way the timed export works, when you set a discharge limit the inverter will not drop below that limit so any house load has to come from grid import, negating the benefits of your export. You have to adjust the export start time to get the result you want

Thank you, just means I will have to keep altering the export time period dependant upon how full the battery is unless there is a way around it ?

Paulbooth There is no way to do this with the givenergy app or portal.

There are however third party solutions such as WonderWatt, My Energy Optimiser (both subscription services), Octopus R&D (free), Home Assistant (free but requires a PC, Raspberry Pi or NAS device to run it on) or RubikCube's Android app (£10 one off fee) which needs an Android device to run it on

geoffreycoan thank you for your advice, much appreciated 👍🏽