Mine has stopped holding a charge for more than an hour…that is a full over night charge. Sometimes it will not even turn on or if it does, it shows a full battery charged but is depleted wthin an hour…totally discussed with my Pebble and of do not have the reciept so I am SOL on trying to return it!!! It is file 13 bound!!!
Have you tried a Factory reset and using the stock watch faces to see if that helps? Maybe even deleting and reinstalling the app on the phone.
have you been leaving it on the charger all day