I didn’t see my reply so I will try it again. I bought the Flex 2 through E-Bay. I am not sure how fresh the batteries were, it took 3 days before it was fully charged and the lights worked. I have had perhaps 4 other Fitbit since 2012. I like the Flex 2 because I use the necklace pendant instead of a wristband.
my new Flex 2 is working great now.