If you don't have a Fitbit charger, there are a few alternative ways to charge your device. Here's a detailed answer with various methods you can try:

1. USB Port: Use a USB port on a computer or laptop to charge your Fitbit. Most Fitbit models come with a charging cable that has a USB connector on one end. Plug the USB connector into the USB port, and the other end into your Fitbit device. Make sure the computer is turned on and not in sleep or hibernation mode. This method is convenient as USB ports are commonly available on many devices.

2. USB Wall Charger: If you have a USB wall charger that you use for charging other devices like smartphones or tablets, you can use it to charge your Fitbit as well. Plug the USB end of the charging cable into the wall charger, and the other end into your Fitbit. Ensure the wall charger provides the appropriate power output for your Fitbit model. Refer to your Fitbit's user manual or the official Fitbit website for the recommended power specifications.

3. Portable Power Bank: If you have a portable power bank, you can use it to charge your Fitbit on the go. Connect the charging cable to the USB output of the power bank and the other end to your Fitbit. Power banks are convenient when you don't have access to a wall charger or a computer, making them useful during travel or outdoor activities.

4. Wireless Charger: Some Fitbit models, like the Fitbit Versa or Fitbit Ionic, support wireless charging. You can purchase a wireless charging pad or dock that is compatible with your Fitbit model. Simply place your Fitbit on the charging pad or dock, and it will start charging wirelessly. Make sure to check the compatibility and specifications of the wireless charger before purchasing.

5. Fitbit Charging Dock: If you have lost your Fitbit charger but still have the charging dock that came with your device, you can use it to charge your Fitbit. The charging dock is the part that holds your Fitbit and connects to the charger. Place your Fitbit on the dock, and then connect the dock to a power source using a USB cable. This method is specific to Fitbit models that come with a charging dock.

Remember, it's always recommended to use the official charger provided by Fitbit for optimal charging performance. If you've lost your charger, you can purchase a replacement from the Fitbit website or authorized retailers.