Kingsong 16X Crash - 50% Battery, under 20mph? :(

I had my first cut out today... I wasn’t riding hard, or going fast... I had about 43% battery left on the KingSong 16X. The day before, I took the same route, slightly slower with only 12% battery remaining, without issue. Didn’t get much advanced warning to slow down or get off. Not sure what to take home from this situation, just yet.