Hi John
As the charging indicator returns to red upon removal from the charger, check that:
All plastic wrap has been removed from both ends and both sides of the charging cable (check closely on the head of the charger).
Under normal operation, charging should only take up to around 2.5 hours for a full charge.
More information:
Check your battery and charge your Apple Watch - Apple Support
If the issue persists after following these steps, contact Apple Support (mail-in service may be available) or make a Genius Bar reservation with a view to having your watch and/or power accessories checked under warranty:
https://www.apple.com/support/watch/contact/
By the way: although your query is on a related subject, it is different to the original question here, which has already been answered. A different question should be asked in a new thread. If others later have the same query, this also makes it easier for them to find - hopefully along with an answer.
More information: Find answers and ask new questions