Battery woes of not so long ago
It is interesting to note the problems that occurred several decades ago when we made the switch from lead acid batteries, now ancient for commercial aerospace applications, to NiCads. The NTSB apparently recorded over a dozen incidents in one year back in the early 1970's. There were alarms sounded, and the same sort of doomsday talk and whinging that is heard today about the lithium-based types in the 787 filled the air back then.
After the teething issues were resolved, NiCads quickly became an industry standard for both private and commercial transport category aircraft. There were no crashes or fatal mishaps.