04-23-2016 13:28
04-23-2016 13:28
04-24-2016 08:51
04-24-2016 08:51
@Conniel79 Welcome to the Fitbit Community! Try to restart your Zip first. Also, checking the inside connectors to make sure they are having proper contact with the battery is great. Sometimes it is need to lift up the metal tab inside to make sure it will touch the battery. Check here to follow the process. If non of this works; I will recommend to report the problem to customer support for further solutions. You can check the warranty here.
Try that out and let me know how it goes!