I took my Mavic mini out today and when I took the charging hub out of the fly more case, it was warm to the touch. I have been storing all three batteries in there fully charged since the last flight on Sunday (4 days). It wasn’t super hot but I’m concerned the that if the problem worsened it would become a fire hazard and it seems like it shouldn’t be getting warm when idle. Should I not keep the batteries in the charger? Has anyone else had an issue with this?

I've never had mine stored that long fully charged, but never had an issue with three days.