Rechargeable batteries can only be recharged so many times and after 10 years cell damage would occur. But regular batteries are worse. The megaphones takes C or D, either one would burst before 10 years.
After that scene I could not get that out of my mind, and so I lost part of the enjoyment of a movie.
Sure it is a very small thing and some can easily overlook it, but if the viewer is to believe in what we watch they have to hold true to science, at least to some degree.
I was disappointed because of this one single minor little bitty flaw.
Okay granted there will be ones to step forward with an explanation for the batteries.
But fact is, the science does not support them lasting that long.