A Fitbit Sense 2 that will not charge nearly always has dirty contacts, a charger that is not seated or a cable or adapter that cannot supply power, and the cure is a patient set of checks. The Sense 2 charges through a magnetic cable that clips to the back of the watch, where small metal pins meet pads, and sweat, lotion and skin oil leave a film on both that blocks the connection. Remove the charger, wipe the pins on the cable and the pads on the watch with a soft, dry cloth and, for stubborn residue, a cotton swab dampened with a little isopropyl alcohol, letting everything dry fully.
The checks in more detail
A soft, dry toothbrush clears lint from around the pins. Then align the cable so that the pins sit squarely on the pads: it should snap on with a magnetic pull, and the watch shows a charging icon or a lightning bolt when it is working. If the icon does not appear, test the supply. Plug the cable into a wall adapter of the usual USB type, five volts and about one amp is enough, and not a computer port or a hub, and try another outlet.
A cable with a bent or worn plug may fail, and a USB port on a computer or a TV may supply too little power. If you have another Sense 2 or a compatible Fitbit charger, test it, because Sense 2 uses its own cable and an older Sense cable is not the same shape. A watch that has fully discharged may need to charge for ten or twenty minutes before the screen shows anything, so leave it connected and do not press buttons. Restart the watch by holding the side button for about ten seconds if it is responsive, and Fitbit describes a force restart with button presses for a watch that is stuck.
Make sure the watch is dry, since moisture on the contacts stops charging; wipe it and wait. Update the Fitbit app on your phone, and sync when the watch wakes. If the watch charges but drains quickly, check the always-on display and the number of notifications and workouts, since these change battery life from days to hours. A battery that has aged over two years may hold less. If the watch will not charge with a clean, dry cable and a known-good adapter, contact Fitbit with the serial number for repair or replacement.
Differential
Likely causes of “Fitbit Sense 2 will not charge”, and how to tell them apart
- 1
Dirty pins and pads
What separates it The charger does not register
How to confirm Wipe with a dry cloth and a touch of alcohol
- 2
A cable that is not seated
What separates it No charging icon
How to confirm Align until it snaps on
- 3
A weak adapter or computer port
What separates it Very slow or no charging
How to confirm Use a wall adapter
- 4
A deeply discharged battery
What separates it The screen stays dark
How to confirm Charge for twenty minutes
- 5
Moisture on the contacts
What separates it Charging starts and stops
How to confirm Dry the watch and wait
Before you touch a setting
Record this first — changing settings destroys the evidence
- Whether the charging icon appears
- The adapter and cable used
- Whether the contacts look dirty
- How old the watch is
Try in this order
0 of 6 completedClean the pins and pads
ReversibleDry cloth, then alcohol.
Align the cable
ReversibleUntil it snaps on.
Use a wall adapter
ReversibleNot a computer port.
Leave it for twenty minutes
ReversibleIf it was flat.
Force restart
ReversibleIf it is stuck.
Contact Fitbit
ReversibleIf nothing works.
Model-specific
What is true of this model and not of its siblings
- Magnetic cable
- Pins must sit on the pads.
- Wall adapter
- Computer ports may supply too little.
Stop boundary
When this stops being a self-service repair
- !If it will not charge with a clean cable and a good adapter, contact Fitbit with the serial number
- !If the back is swollen, stop using it
- !Keep the receipt
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why will my Sense 2 not charge?+
Dirty contacts or a poorly seated cable.
Can I use the old Sense cable?+
No, the Sense 2 charger differs.
How long should it take?+
A couple of hours from empty.
Is the battery worn?+
After two years it may hold less.