Last week, I put my watch on the charger and nothing happened. Did a complete shut down and restart but not difference. Left it on the charger overnight and it was completely dead other than getting the time when pressing the crown. Later that day, I tried it again and it started charging and worked thereafter until last night. Now it has the same behavior as before. Is this a sign of a dying battery? If so, who in the USA can replace the battery for a better price than Apple? TIA.