Hi James,
my mooshimeter was shipped with a dead battery(one cell had 1.2V and one had 0V).
I inserted new ones but they only lasted for two days with a logging interval of 10 seconds.
Four days ago I inserted a different brand, but it did not last until today(without logging, no bluetooth connection).

I did not measure if the new batteries also had this strange fact that only one of them is empty.
Do you have any idea why this happens?