Hi Eugene,

The Mooshimeter opens a new log file under 2 circumstances:

1. If the user toggles logging off and on again.
2. If there’s an error writing to the card.

I think you are experiencing errors writing to the card. When you are connected to the phone, the meter is awake all the time, and never has to put the SD card to sleep. When you disconnect the phone, the meter puts the SD card to sleep and wakes it up every few seconds (depending on your settings) to write. If you are seeing continuous files while connected but broken files after you disconnect, I think there’s an issue waking up the SD card.

Things to try:
– Using a different SD card.
– If you’re on Android, the beta release of the app has new firmware bundled that improves logging behavior and may improve compatibility with your card
– Setting the meter logging interval to “MAX”. This will hurt battery life, but it will make the SD card never go to sleep.

I hope one of these helps, sorry for the trouble. Best
~James