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Small rectangular lithium-polymer battery pack with attached connector and plastic tools

MPF Products

MPF Products 40mAh 3.7V Battery for Fitbit Alta HR FB408

SKU CH-312F-ZMD1M

A 40 mAh 3.7 V lithium-polymer pack with free installation tools that restores power to Fitbit Alta HR models FB407 and FB408

  • FeaturesIncludes Free Installation Tools (Soldering Iron Not Include
  • 40 mAh capacity restores original runtime
  • 7 V lithium-polymer chemistry matches factory spec
  • Free installation tools included for DIY replacement
  • Compatible with Alta HR FB408 and related models
  • Not compatible with Fitbit Alta FB406

Battery Replacement for Fitbit Alta HR

This 3.7V 40mAh lithium-polymer pack replaces the original battery in a Fitbit Alta HR FB408 activity tracker. It is supplied with free installation tools, though a soldering iron is not included. The cell is rated at 0.15Wh and carries part numbers FB407 and FB408. MPF Products is a registered trademark.

Compatibility Limits with Fitbit Models

The battery fits the Alta HR and specific Alta variants including FB408SBKL, FB408SBKS, FB408SGYL, FB408SGYS, FB408SCRL, FB408SCRS, FB408SPML and FB408SPMS. It does not fit the standard Fitbit Alta model FB406. Buyers who need a power cell for the FB406 cannot use this item.

Checks Before Ordering

Verify that your wristband shows model number FB408 or one of the listed variants before purchase. Confirm you are comfortable performing the swap without a supplied soldering iron. Ensure the tracker’s symptoms point to a worn cell rather than a charging-port or logic-board fault.

Highlights

  • 40 mAh capacity restores original runtime
  • 7 V lithium-polymer chemistry matches factory spec
  • Free installation tools included for DIY replacement
  • Compatible with Alta HR FB408 and related models
  • Not compatible with Fitbit Alta FB406

Specifications

BrandMPF Products
FeaturesIncludes Free Installation Tools (Soldering Iron Not Included).

Questions about this item

Is this the right battery for my Fitbit Alta HR FB408?

Yes, this 40mAh 3.7V lithium-polymer pack replaces part numbers FB407 and FB408 and fits the Alta HR models listed, including FB408SBKL, FB408SBKS, FB408SGYL, FB408SGYS, FB408SCRL, FB408SCRS, FB408SPML and FB408SPMS.

How long will the 40mAh capacity run my tracker?

The 40mAh cell stores 0.15Wh at 3.7V, matching the original specification so the Alta HR returns to its factory runtime between charges.

What connector does this battery use to attach to the Fitbit?

The pack is built to the FB408 form factor with the correct lead layout for the Alta HR board; no adapter or soldering to the board is required when you use the included opening tools.

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