One of the biggest problems with Seiko solar watches is the fact that they run out of energy if not in the sunlight, causing them to not tell accurate time. This problem worsens during the fall and winter when the sun isn't out as long and people wear long sleeves.
A problem with leaving the watch in the sunlight for too long is the discoloration of the band. If it is left on the dashboard of a car to charge in extremely hot conditions, some of the internal mechanisms can malfunction. Degraded oils and contaminated parts of the watch can cause it to not charge as completely as it should.