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When not charging the device it ruins the battery. Once They have been charged you need to keep charged. It ruins the battery when its not.
But try these steps
Please clean the contacts
http://help.fitbit.com/articles/en_US/Help_article/My-tracker-s-battery-isn-t-charging/?q=not+chargi...
Then Do a Restart @least 3 times
http://help.fitbit.com/articles/en_US/Help_article/1186/?q=restart&l=en_US&fs=Search&pn=1
Wendy | CA | Moto G6 Android
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