During the cold weather in November the battery discharged below 4% on several occasions and one night showed 0% (even though the setting is 4% minimum). Charging from solar seems OK and also I think on one very grey day the battery was charged from the grid back to the 4% minimum power level setting . The battery now has solar power charge up to 55% capacity but didnt discharge at more than 100W overnight or this morning . Even when I activate the kitchen kettle the system draws power from the grid , not the battery . I have just spoken with Giv energy help line at the suggestion of a local Giv energy installer (my installer ceased trading) . The Giv Energy help line was very helpful and they are going to try a software update