at what percentage should a SPARK battery be stored at for a long period of non use , i thought 50 to 65% is about right . that would be about 3 green lights .
I typically fly until the battery is down to around 30%. The important thing is to never store a fully charged battery, unless you’re planning on using it within a couple of days.
as of now i have not had a battery discharge when not using it .i know that after 10 days the spark's batteries will go into discharge mode , is that storage mode and of what percentage is it . 40 to 55 % is storage mode voltage . below is a chart of LI PO batteries pack voltage .
in 10 days the smart batteries will go into low power mode and then a few weeks later, reduce even more.
I would only trust that chart to "dumb" LiPo packs because of everything integrated within the DJI battery.