I think this might be what I was thinking of, don't know if it...

I think this might be what I was thinking of, don't know if it would be relevant in Ban Pha Dan:

"On the discharge cycle, the ZCell flow battery is discharged first due to its propensity for deep and frequent cycling while holding the ‘sprinter’ lithium battery in reserve for cold overcast Canberra days. This, in turn, minimises discharge cycles for the lithium battery, thereby maximising its life, which is diminished as a function of discharge cycle frequency and depth."

https://redflow.com/resources/canberra-house-models-hybrid-grid-with-redflow/