Free Shipping on Domestic Orders $75+

Introduction

Follow this guide to replace a worn-out or dead battery in your Logitech MX Master 4 wireless mouse.

It’s natural for batteries to lose capacity as they age. If your mouse dies quickly and doesn't hold a charge, it may be time to replace the battery.

For safety, perform this repair when your battery is below 15% charge. Any charged lithium-ion battery can be hazardous if punctured or damaged. If your battery looks puffy or swollen, take appropriate precautions.

What you need

Step 1 Prepare your mouse for disassembly

Logitech MX Master 4 Battery Replacement, Prepare your mouse for disassembly: step 1, image 1 of 3

Logitech MX Master 4 Battery Replacement, Prepare your mouse for disassembly: step 1, image 2 of 3

Logitech MX Master 4 Battery Replacement, Prepare your mouse for disassembly: step 1, image 3 of 3

Flip the mouse's power switch down into the OFF position and unplug any cables.
The mouse's unique shape prevents it from laying flat. If you need to, lay it down on a soft towel to prevent wobble.

Edit

Step 2 Remove the case screws

Logitech MX Master 4 Battery Replacement, Remove the case screws: step 2, image 1 of 2

Logitech MX Master 4 Battery Replacement, Remove the case screws: step 2, image 2 of 2

Use a Phillips screwdriver to remove the six screws securing the two halves of the mouse together:
Five 4.3 mm‑long screws
One 6.3 mm‑long recessed screw

Edit

Step 3 Unclip the front of the mouse

Logitech MX Master 4 Battery Replacement, Unclip the front of the mouse: step 3, image 1 of 3

Logitech MX Master 4 Battery Replacement, Unclip the front of the mouse: step 3, image 2 of 3

Logitech MX Master 4 Battery Replacement, Unclip the front of the mouse: step 3, image 3 of 3

Two strong, plastic clips still secure the front of the mouse.
Insert the flat end of a spudger in the seam between the two halves of the mouse, near the power switch.
Slide the spudger along the seam to the very front of the mouse.
Gently pry the bottom half of the mouse away from the top half, until you feel and hear the first clip release.
You should only have to pry a small amount. If the mouse doesn't unclip, remove the spudger and start over.

Edit

Step 4 Separate the halves

Logitech MX Master 4 Battery Replacement, Separate the halves: step 4, image 1 of 3

Logitech MX Master 4 Battery Replacement, Separate the halves: step 4, image 2 of 3

Logitech MX Master 4 Battery Replacement, Separate the halves: step 4, image 3 of 3

Don't try to fully separate the two halves yet—a ribbon cable still connects them.
Grip the top half of the mouse in one hand, and the bottom half in your other hand.
Slowly pull the back of the mouse apart until you feel the last clip on the front release.
During reassembly, firmly pinch the mouse together near the front to engage the two clips.

Edit

Step 5 Prop up the top half

Logitech MX Master 4 Battery Replacement, Prop up the top half: step 5, image 1 of 2

Logitech MX Master 4 Battery Replacement, Prop up the top half: step 5, image 2 of 2

Flip the top half of the mouse over the right side and use a sturdy object to prop it up, so you can access the battery.

Edit

Step 6 Remove the battery screws

Logitech MX Master 4 Battery Replacement, Remove the battery screws: step 6, image 1 of 2

Logitech MX Master 4 Battery Replacement, Remove the battery screws: step 6, image 2 of 2

Use a Phillips screwdriver to remove the three 4.4 mm‑long screws securing the battery.

Edit

Step 7 Remove the battery

Logitech MX Master 4 Battery Replacement, Remove the battery: step 7, image 1 of 3

Logitech MX Master 4 Battery Replacement, Remove the battery: step 7, image 2 of 3

Logitech MX Master 4 Battery Replacement, Remove the battery: step 7, image 3 of 3

Use your fingers to lift the battery straight up and remove it.
During reassembly, press the battery into place until the connector on the bottom edge clicks into its socket.

Edit

Conclusion

Compare your new replacement part to the original part—you may need to transfer remaining components or remove adhesive backings from the new part before you install it.

To reassemble your device, follow these instructions in reverse order.

Repair didn’t go as planned? Try some basic troubleshooting, or ask our Answers community for help.

Reuse or Recycle—Never put discarded electronic parts in household waste. Visit Logitech Recycling to find your nearest recycling points, including the option to mail back old devices to Logitech for free if there’s no convenient solution in your area. You can also take your e-waste to any R2 or e-Stewards certified recycler. And don’t let good working parts or repaired devices die a slow death in your sock drawer—pass them along to someone who can use them.

Share your experience—Leave a comment here or send your feedback directly to Logitech at repair@logitech.com to help shape future repair guides and product design.