Hi Eleanor, this seems to be the manual although you may already have this. The battery does need to maintain a 10% charge and so there may be an automatic top up from the grid to do this (there should be a setting for that).
Do you use the SolaX cloud app? If the system has a Wi-Fi connection it can be operated from the app and also the output and operation monitored.
As I mentioned, there will be a little grid use whatever as the system tries to balance solar PV generation, household demand and residual power and the power switching isn’t as fast as demand changes but I wouldn’t expect your export level to be more than 10% of consumption.
If your peaks are at the same time each day, it suggests there’s a setting for that and the SolaX system would be needed to look more closely.
The other thing to think about is if you have a few things switched on at the same time .. it may be that the batteries and or solar cannot meet demand and do the grid fills the gap. We have a. 9kw shower which my system can’t deliver but the batteries provide some, Solar some more (if daytime) and the grid the rest so it’s worth knowing what’s already switched on when switching anything else on