Rectifying Firmware Hangs on Fitbit Charge 5

Fitbit Charge 5 users have reported that the watch can become unresponsive during or after a firmware update. The device may appear to freeze, the display may stay black, or the watch may only show a blinking power icon. This article explains why these hangs happen, how to diagnose the problem, and the precise steps needed to restore normal operation. By following the instructions below you can get your Charge 5 back into working order without losing data or needing a professional repair.

What Causes Firmware Hangs?

A firmware hang can be triggered by a variety of factors that interrupt the normal update process. Understanding the root causes helps you decide which troubleshooting step to try first.

Interference During Update

The Charge 5 communicates with the companion app over Bluetooth Low Energy (BLE). If the phone moves too far away, or if another device on the same frequency (e.g., a Wi‑Fi router or a baby monitor) interferes, the data stream can get corrupted. Firmware packets that fail to reach the watch can leave it in an incomplete state, causing it to loop while waiting for missing data.

Power Loss or Low Battery

The update process requires the watch to stay fully powered. If the battery drains below 20 % during an update, or if the watch is removed from its charging dock before the process finishes, the firmware can be partially written. When the device reboots it may repeatedly try to finish the update, resulting in a freeze.

Software Bugs in the Companion App

Fitbit periodically releases updates for the mobile app. Occasionally, a new version introduces a bug that mis‑reports the update status or fails to send the final handshake packet. If the app thinks the update finished while the watch is still waiting, the watch may hang until the app re‑initiates the handshake.

Incompatible Firmware Versions

If the user manually installs a firmware file that was designed for a different Charge model, the watch will try to write code it cannot execute. The result is a lock‑up that can be difficult to break without a full reset.

Prepare Your Workspace

Before you dive into troubleshooting, gather the items and conditions that will make the process smoother and safer for your device.

• A fully charged phone with the latest Fitbit app installed.
• A stable Wi‑Fi or mobile data connection that does not disconnect during the process.
• The original charging dock or a reliable USB charger that supplies at least 5 V/1 A.
• A quiet, dust‑free environment to prevent accidental movement of the watch during updates.

Make sure you back up any sensitive data—such as health statistics—by syncing your device to the cloud or exporting logs through the app. While firmware updates do not erase user data, a forced reset may erase the device’s local cache.

Step‑by‑Step Guide to Fix Firmware Hangs

The following procedure is designed to resolve most hangs without data loss. If a simpler fix works, you can skip the later steps.

1. Force a Full Restart

The Charge 5 can be restarted by holding the button on the left side for 10 seconds. This wakes the device from a frozen state and forces a soft reboot. If the watch still shows a blinking power icon after a restart, proceed to the next step.

2. Verify Battery Level and Charging

A low battery can stall updates. Plug the watch into its charging dock or use a USB charger for at least 30 minutes before attempting any further steps. Ensure the charging indicator shows a solid green light (or the equivalent on your region’s version).

3. Re‑pair with the Mobile App

Disconnect and reconnect the Bluetooth link between the watch and your phone.

• Open the Fitbit app.
• Go to Account > Your Device > Settings > Forget Device.
• Turn off Bluetooth on your phone, then turn it back on.
• Re‑pair the Charge 5 by following the on‑screen prompts.

Re‑pairing forces a fresh exchange of firmware metadata and can clear any stale connection state.

4. Clear the Cache in the Fitbit App

Sometimes the app caches incomplete data that interferes with updates.

1. In the Fitbit app, go to Account > Settings.
2. Scroll to “Cache Management” and tap “Clear Cache.”
3. Restart the app and let it resync with the watch.

After clearing the cache, attempt to start a fresh firmware update.

5. Initiate a Manual Firmware Update

If the automatic update is stuck, try installing the firmware manually.

1. Visit the Fitbit Support website and download the latest Charge 5 firmware file.
2. In the Fitbit app, navigate to Account > Settings > Firmware Update.
3. Select “Choose Firmware File” and locate the downloaded file.
4. Follow the on‑screen instructions to flash the firmware.

Important: Do not remove the watch from its charger or turn off your phone during this process. If you need to pause, pause the update and resume immediately after you reconnect.

6. Perform a Hard Reset

If the watch still hangs, a hard reset will erase local settings but preserve cloud‑synced data.

1. Hold the button on the left side and the button on the right side simultaneously for 10 seconds.
2. Release both buttons when the screen flashes.
3. Follow the on‑screen prompts to complete the reset.

After the reset, set up the watch again through the Fitbit app. Once the device has re‑connected, a firmware update should start automatically.

7. Check for App or OS Bugs

If the problem recurs after a reset, you may be dealing with a bug in the Fitbit app or your phone’s operating system.

• Update your phone’s OS to the latest stable release.
• Delete the Fitbit app completely, then reinstall it from the official store.
• Restart your phone and allow the app to sync with your device.

A clean installation often resolves hidden corruption that can cause firmware hangs.

8. Contact Fitbit Support

When all the above steps fail, it is time to involve Fitbit’s technical team. Prepare the following information:

• Device model and serial number (found on the back of the watch or in the app under Account > Device).
• Steps you have already taken.
• Any error messages or screenshots.

Reach out via the official support page, email, or phone. Fitbit may provide a replacement device if the firmware hang is a result of a manufacturing defect.

Advanced Troubleshooting Options

For users comfortable with deeper technical interventions, the following options may resolve stubborn hangs.

A. Use the Fitbit Desktop App

The desktop companion app can sometimes handle updates better than the mobile app. Download the latest version from Fitbit’s website, connect your Charge 5 via Bluetooth, and attempt the update again.

B. Reflash Using a USB Dongle

If your Charge 5 supports USB debugging (rare for consumer models), you could connect it to a computer and use specialized flashing tools. This is generally not recommended unless instructed by a professional, as it can void warranties and permanently damage the device.

Preventing Firmware Hangs in the Future

Once your Charge 5 is back online, adopt best practices to reduce the likelihood of future freezes.

• Keep the device charged to at least 30 % before starting an update.
• Ensure the watch remains within a 10‑meter radius of the phone during the update.
• Avoid using the watch while it is charging and updating; use a stationary location.
• Turn off airplane mode on your phone during updates to prevent interference.
• Regularly back up health data to the cloud or export it manually.

By following these habits, you’ll give your Charge 5 the best chance of smooth firmware maintenance.

Frequently Asked Questions

Q: Will a firmware hang erase my health data?
A: No, the data stored in the cloud remains safe. A hard reset may clear local cache but not cloud‑synced information.

Q: Can I update the firmware without my phone?
A: The Charge 5 relies on the Fitbit app for firmware distribution. There is no standalone update mechanism.

Q: Why does the watch keep blinking after a reset?
A: A blinking power icon indicates the device is attempting to finish an incomplete update. Let the watch stay connected to its charger for at least an hour.

Q: Is there a difference between a soft reset and a hard reset?
A: Yes. A soft reset (button hold for 10 seconds) restarts the watch; a hard reset (both buttons for 10 seconds) restores factory settings.

Final Thoughts

Firmware hangs on the Fitbit Charge 5 are frustrating but generally solvable with systematic troubleshooting. The key is to maintain power, keep the connection stable, and give the device time to finish writing the new firmware. Most users can recover their device without losing data or requiring professional service. If you still face issues, Fitbit’s support team is equipped to help. By staying proactive—keeping the app and phone updated and following the steps above—you can keep your Charge 5 running smoothly for years to come.