Yeah with the issue you are explaining it could either be a weak fuse or a bad battery. I see wave batteries go bad all the time. Encore doesn't always replace batteries unless they are causing issues while in the shop. I recommend replacing all 4 but it sounds like you caught this issue early so it shouldn't have caused any damage to the other 3 yet, but there still is a chance that just installing 1 will only temporarily fix your issue.
You can check the battery manufacture year by looking for the silver stick with a letter and 2 numbers on it next to the recycling logo. The 2 numbers are the manufaure year.