Garmin Fenix 5x Battery Replacement

Remove the five screws surrounding the display using a Torx T7 bit.

Please take note of how tight they are so you can achieve the same torque during final reassembly.

Carefully lift up the display.

Remove the green sticker covering the two press connectors.

Save this for later; you might be able to reinstall it at the end. If not, no worries.

Remove the display ribbon cable press-fit connector.

Remove the top conductive piece. Take note of its orientation because this will be important later.

Remove the sensor ribbon cable press-fit connector.

Use a Torx T5 bit to remove the mainboard screws. Then carefully pry up the mainboard.

I recommend prying the same way as shown in the image; it is easiest and least likely to cause damage.

Carefully remove the battery connector by lifting up, not by pulling out.

Remove the battery from the mainboard by prying gently and using isopropyl alcohol to dissolve the adhesive.

This step may be very difficult, and some very gentle heat could be helpful, but be careful not to puncture or in any other way damage the battery cell.

Plug in your new battery. The battery wires may be longer than the original, so orient the battery in a way so that the wires do not interfere with the mounting holes of the mainboard.

Reinsert the mainboard. If your replacement battery is a different size/shape than the original, you may have to reposition it a few times before the board will fit.

Replace both screws and do so carefully to make sure you do not pinch the battery wires.

Reconnect both ribbon cables and replace the small conductive piece on the top side, ensuring correct alignment with the pins on the mainboard.

(optional) If you are able to replace the small green sticker covering the press connectors for the ribbon cables, do this now.

Then, if you would like, you may power on your watch to confirm functionality before final reassembly.

Ensure that the o-ring is clean and properly in place in its groove. This is what keeps everything waterproof, so if you use your watch in water, this is very important to check.

If during the repair you got dust or other debris inside the groove or around the o-ring, carefully clean with alcohol around the ring and the sealing area on the underside of the display.

Insert the screws on the face of the watch.

First, gently tighten all screws, and then proceed to fully tighten opposite pairs at a time to ensure a proper and complete seal.

Do not over-tighten screws; try to achieve the same torque as you noticed at the start of the repair. Check around the edge where the two pieces meet; at most, you should see a hairline gap.

Test your watch's charging, data transfer, and other functionality. For most Li Ion batteries, it is recommended to complete one full charge and discharge cycle before normal use.