I am asking this on behalf of someone who doesn't have a computer.  They say 
they were reading a book on battery power with the player unplugged when 
after a clap of thunder the player said, "Battery Low."  They had several 
hours of battery power left before the thunder clap, but lost it all 
afterwards.  Then the next time they charged it up, it drained down to the 
same point when there was again no power.  Could the thunder storm or 
lightning caused this with the player unplugged, or was this purely 
coincidental?  They had the standard player which they sent back for another 
one after this incident.  I think the NLS digital format is the best ever 
offered by NLS, but I find this series of events very strange.  I could 
understand it if the player was plugged in, but not unplugged and on battery 
power.  73.
Harvey