Spark from wire in battery, unclear cause

[Pacto]

I was putting a 48V Himiway Escape Pro battery back inside its case when a spark suddenly flew from the red wire. The burn marks can be seen in the photos. What's strange is that the wire did not appear to be in contact with anything else, and there's still continuity in both of the two fuses of the battery. The charging and output voltage also appear to be normal afterwards. Any idea on what could have caused the spark? And is it likely to present a hazard from then on?

 

[DieselTech]

I was putting a 48V Himiway Escape Pro battery back inside its case when a spark suddenly flew from the red wire. The burn marks can be seen in the photos. What's strange is that the wire did not appear to be in contact with anything else, and there's still continuity in both of the two fuses of the battery. The charging and output voltage also appear to be normal afterwards. Any idea on what could have caused the spark? And is it likely to present a hazard from then on?
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Your lucky you did not have a major fire on your hands. Is that a metal style battery case? If soo the metal case cut into the wiring. Yes you need to fix that immediately.