I purchased this watch hoping to be rid of battery power or a manual (finger) wind up.  The SNK809 worked great for the first six months.  After this period, the watch would not take a mechanical charge at night (sleep).  I guess I didn't move enough to generate enough energy to 'charge' the movement.  I would have to reset the watch each morning.  This worked for several months than the SNK809 stopped working completely.  I'm sorry to say perhaps this Seiko 5 is inferior to the standard Seiko.  I will not purchase another Seiko 5.