Sorry, fell behind in the forums!
You’re right, the batteries should not have died that quickly. Hibernation should not be necessary.
The meter is in sleep/standby mode whenever it does not have an active bluetooth connection. When the meter is connected, the LED will be flashing every time it takes a sample, which is several times a second on the default settings. If the meter is in standby it will only give a very small flash every 10 seconds.
Was the meter connected the whole time? If connected the battery life of the meter is much shorter.
You can disconnect from the iOS app by pressing the “back” button in the top left corner of the text view page. Pausing the stream when the app is backgrounded is already in the feature requests on github, will try to push that soon.