I have set a battery minimum SOC to 8% (limited solar and no point charging from Grid). I have noticed that the battery quickly drops from the 8% minimum down to 5%-7% within 3hrs or so (with no actual battery discharge) and then regularly charges back up to the 8%. I almost certain the battery never did this when set at minimum SOC of 4%. Is there something wrong here? Why cant the battery hold it's charge over such a short period? Screenshot attached.
TvdK Mine does something similar - I set a min of 20% until about 4:30pm to hold some battery back for peak rate.
I think it can drift downwards because it is re-evaluating the SoC while the battery is idle. I understand that it needs to be idle for a long-ish period for the chemistry to settle down and get a true reading. And then a feature (which I think is newish with recent firmware ?) seems to be to slowly charge the battery up, at around 280W, until it gets back up to the configured minimum.
I'm guessing you don't have a tariff with a cheap overnight period to charge the battery up ? So perhaps it rarely gets to 100% at this time of year? That may have a negative impact on how accurately the BMS can track the charge level.
DD Yea no cheap overnight rates unfortunately and solar only occasionally charging up to the 80's if lucky. Still seems odd that it drifts so quickly. I suppose I could charge up the battery and pause it to see how it holds it SOC to compare.