Don’t know about the cuttoff percentage since I have a different battery and hand throttle, you might find it here: SP140 - Battery low power cut off mechanism & thresold
The storage voltage of lithium is around 3.8v/cellx24 cells=91v.
-For long-term storage, storing at 40% battery capacity is best for maximizing the lifespan of the cells. For the SP140, 40% battery capacity is at roughly 86 volts.