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Introduction

Use this guide to replace a worn-out or dead battery in your Xiaomi Mi 8.

If your battery is swollen, take appropriate precautions. For your safety, discharge your battery below 25% before disassembling your phone. This reduces the risk of a dangerous thermal event if the battery is accidentally damaged during the repair.

You’ll need replacement adhesive to reattach components when reassembling the device.

  1. Apply a heated iOpener to the rear glass to loosen the adhesive beneath the edges. Apply the iOpener for at least two minutes.
    • Apply a heated iOpener to the rear glass to loosen the adhesive beneath the edges. Apply the iOpener for at least two minutes.

  2. Secure a suction handle to the lower edge of the rear glass, as close to the edge as possible. If the phone's rear glass is cracked, the suction handle may not stick. Try lifting it with strong tape, or superglue the suction handle in place and allow it to cure so you can proceed. Lift the rear glass with the suction handle to create a gap between the glass and the frame.
    • Secure a suction handle to the lower edge of the rear glass, as close to the edge as possible.

    • If the phone's rear glass is cracked, the suction handle may not stick. Try lifting it with strong tape, or superglue the suction handle in place and allow it to cure so you can proceed.

    • Lift the rear glass with the suction handle to create a gap between the glass and the frame.

    • Insert an opening pick into the gap.

    • If the glass wont budge, apply more heat to further soften the adhesive. Follow the iOpener instructions to avoid overheating.

    • Slide the opening pick to the bottom right corner of the phone.

  3. Insert a second opening pick and slide it to the bottom left corner  to cut the adhesive. Leave the opening picks in place to prevent the adhesive from resealing.
    • Insert a second opening pick and slide it to the bottom left corner to cut the adhesive.

    • Leave the opening picks in place to prevent the adhesive from resealing.

  4. Insert a third opening pick at the bottom left corner. Start to slide the opening pick from the bottom left corner along the side of the Xiaomi Mi 8 to cut the adhesive. Be aware of the fingerprint flex cable and only insert the tip of the opening pick. If insert to deep, you can cut the cable by accident.
    • Insert a third opening pick at the bottom left corner.

    • Start to slide the opening pick from the bottom left corner along the side of the Xiaomi Mi 8 to cut the adhesive.

    • Be aware of the fingerprint flex cable and only insert the tip of the opening pick. If insert to deep, you can cut the cable by accident.

    • As the adhesive cools down it gets harder to cut. If necessary use your iOpener to reheat it.

    • Leave the opening pick in the top left corner to prevent the adhesive from resealing.

  5. Insert a fourth opening pick under the top left corner of the rear glass. Slide the opening pick along the top to cut the adhesive.
    • Insert a fourth opening pick under the top left corner of the rear glass.

    • Slide the opening pick along the top to cut the adhesive.

    • Leave the opening pick in the top right corner to prevent the adhesive from resealing.

  6. Insert a fifth opening pick at the top right corner of the phone. Slide the opening pick along the right edge to cut the remaining adhesive.
    • Insert a fifth opening pick at the top right corner of the phone.

    • Slide the opening pick along the right edge to cut the remaining adhesive.

    • Don't try to remove the rear glass all the way yet. The fingerprint flex cable is still connected to the motherboard.

  7. Carefully lift the rear glass and fold it to the left side to access the fingerprint flex connector. Carefully lift the rear glass and fold it to the left side to access the fingerprint flex connector.
    • Carefully lift the rear glass and fold it to the left side to access the fingerprint flex connector.

  8. Use a spudger to pry up and disconnect the fingerprint flex cable. Remove the rear glass.
    • Use a spudger to pry up and disconnect the fingerprint flex cable.

    • Remove the rear glass.

    • Before installing new adhesive for reassembly, remove any remaining adhesive from the phone, and clean the glued areas with isopropyl alcohol and a lint-free cloth.

    • After installing the rear glass, apply pressure for several minutes to help the adhesive form a good bond. A stack of heavy books on top of the phone works well.

  9. Remove the ten screws that secure the motherboard cover.
    • Remove the ten screws that secure the motherboard cover.

    • Eight Phillips #00 screws (3.4 mm length)

    • Two Phillips #00 screws (3.5 mm length)

  10. Slide an opening pick under the right side of the motherboard cover. Twist the opening pick sideways to pry up and slightly lift the motherboard cover.
    • Slide an opening pick under the right side of the motherboard cover.

    • Twist the opening pick sideways to pry up and slightly lift the motherboard cover.

  11. Carefully remove the motherboard cover including the NFC antenna. Carefully remove the motherboard cover including the NFC antenna.
    • Carefully remove the motherboard cover including the NFC antenna.

  12. Use a spudger to pry up and disconnect the battery flex cable located at the bottom of the motherboard. Use a spudger to pry up and disconnect the battery flex cable located at the bottom of the motherboard.
    • Use a spudger to pry up and disconnect the battery flex cable located at the bottom of the motherboard.

  13. Use a pair of tweezers to peel the black ends of the adhesive tabs off the battery. Use a pair of tweezers to peel the black ends of the adhesive tabs off the battery. Use a pair of tweezers to peel the black ends of the adhesive tabs off the battery.
    • Use a pair of tweezers to peel the black ends of the adhesive tabs off the battery.

  14. For the following steps:
    • For the following steps:

    • The adhesive tab underneath the battery can rip very easily. Make sure you pull out the tab in a slow and steady motion and at a flat angle. To prevent the adhesive tab from ripping, it's helpful to twist it around the tweezers.

  15. Pull out the first adhesive tab from underneath the battery. Pull out the first adhesive tab from underneath the battery.
    • Pull out the first adhesive tab from underneath the battery.

  16. Use a pair of tweezers to pull out the second adhesive tab from underneath the battery. In case one of the adhesive tabs rips and it‘s not possible to pull it out completely, you can use isopropyl alcohol or a heated iOpener to loosen the adhesive. After the adhesive is soft enough use a prying tool such as an opening pick or a plastic card to pry out the battery.
    • Use a pair of tweezers to pull out the second adhesive tab from underneath the battery.

    • In case one of the adhesive tabs rips and it‘s not possible to pull it out completely, you can use isopropyl alcohol or a heated iOpener to loosen the adhesive. After the adhesive is soft enough use a prying tool such as an opening pick or a plastic card to pry out the battery.

  17. Use an opening pick or plastic card to pry the battery out of its recess until you can get a good grip. Use an opening pick or plastic card to pry the battery out of its recess until you can get a good grip.
    • Use an opening pick or plastic card to pry the battery out of its recess until you can get a good grip.

  18. Remove the battery. Reusing a deformed or bent battery after it has forcefully been removed, is a potential safety hazard. Replace it with a new battery.
    • Remove the battery.

    • Reusing a deformed or bent battery after it has forcefully been removed, is a potential safety hazard. Replace it with a new battery.

    • Remove any remaining adhesive from the midframe, and clean the glued areas with isopropyl alcohol and a lint-free cloth before applying new adhesive.

Conclusion

If possible, turn on your phone and test your repair before installing new adhesive and resealing the phone.

Secure the new battery with pre-cut adhesive or double-sided adhesive tape. In order to position it correctly, apply the new adhesive into the phone at the places where the old adhesive was located, not directly onto the battery. Press the new battery firmly into place.

To reassemble your device, follow these instructions in reverse order. Apply new adhesive where necessary after cleaning the relevant areas with isopropyl alcohol (>90%).

For optimal performance, calibrate your newly installed battery: Charge it to 100%, and keep charging it for at least two more hours. Then, use it until it shuts off due to low battery. Finally, charge it uninterrupted to 100%

Take your e-waste to an R2 or e-Stewards certified recycler.

Repair didn’t go as planned? Check out our Answers community for troubleshooting help.

6 other people completed this guide.

Dominik Schnabelrauch

Member since: 11/23/2016

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4 Comments

Thanks ! Its helps me alot

Andre Maseliku - Reply

excellent, thanks

Ronald - Reply

Echt Klasse, allerdings sind es 8 schwarze schrauben bei der Mainboard Abdeckung. Ansonsten echt top Anleitung, vielen Dank

Kristijan Likarevic - Reply

Die deutsche Übersetzung war veraltet, ich habe sie aktualisiert. Danke! Viel Spaß mit deinem Xiaomi.

Fabian Neidhardt -

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