Your Smart Water Bottle can save many sips and can memorize when you took them so you don't have to worry if the day ended and you did not sync; however, it is recommended not to stay a long time without syncing, because you might exceed the number of sips that the bottle can retain. Try to sync at least once every 3 days.
The more you drink without syncing, the longer it will take to sync your data the next time you connect to INGO app. Your best option is to benefit from the background sync feature which can make the whole thing hassle-free.
INGO can automatically sync with your Smart Water Bottle if you set location permissions to "Always" on iOS or "Allow all the time" on Android. Location permissions are needed for INGO to discover that the bottle is nearby in order to initiate communication with it in the background.