Xiaomi Mi 9 battery repair guide

The battery life is low, your Mi 9 keeps crashing or won’t charge.

  • Xiaomi Mi 9
  • 12 Steps
  • Medium
  • 45 min.
Go to the guide

Give your Xiaomi Mi 9 full power again with a new battery

In this guide, we will show you how to change the battery of your Xiaomi Mi 9. This step is necessary if you are no longer satisfied with the battery life of your device. This can show up in many ways: Your phone will crash during heavy use. It can no longer be fully charged to 100%. Or you can no longer switch on the Mi 9 at all. Or you notice a significant difference and despite the same usage you can't get through an entire day.

These are all signs that you should change your battery. Our instructions will help you to do this, and will guide you step by step to more power.

The battery is glued in the housing with easily removable adhesive strips. This makes changing the battery easier than with other devices. You can use tape from iPhone 5/5s to reattach the new battery.

Required tools

  • Flat Picks

    Flat Picks

    You need a very flat tool such as a flat pick to pry out parts that are glued in place.

    €2.00 at the iDoc store
  • For storing screws

    For storing screws

    We recommend storing your screws so you don’t mix up the various screws and small parts.

    €10.00 at the iDoc store
  • iPlastix

    iPlastix

    Taking apart the little pieces in your smartphone can be a big pain. The iPlastix is tough but thin with a blade thickness of just 0.15 mm, so it fits into even the smallest spaces, like the gap between the display and frame or under the logic board. The iPlastix is made of durable plastic and designed for a good grip, making this convenient tool the perfect assistant for every smartphone repair.

    €10.00 at the iDoc store
  • iSclack

    iSclack

    You can’t repair your iPhone or iPad until you get the device open. That may sound simple, but it can be a very tricky, complicated process. How can you hold onto everything, and how do you take apart the different pieces? How do you do that without breaking something else? The handy iSclack opening tool makes opening your device a lot simpler and safer. The two suction cups face each other to grip your display and back cover. The handle works like a pair of pliers so you only need one hand to move both parts. Thanks to the included screen covers, you can use the iSclack even on a cracked display.

    €15.00 at the iDoc store
  • Tweezers

    Tweezers

    We recommend using tweezers to remove screws and various small parts from your device.

    €10.00 at the iDoc store
  • Steel Laboratory Spatula

    Steel Laboratory Spatula

    You need a flat and sturdy prying tool to disconnect glued parts.

    €7.00 at the iDoc store
  • Suction cup

    Suction cup

    A suction cup is perfect for lifting smooth surfaces such as displays or rear glass panels.

    €2.00 at the iDoc store
  • Phillips PH00 screwdriver

    Phillips PH00 screwdriver

    You need the right screwdriver for removing PH00 screws.

    €13.00 at the iDoc store
Show all replacement parts for the Xiaomi Mi 9 

Replacement parts and tools for this repair

Our tools plus the right spare part help you fix your device easily.

for €59.00

Getting started with the repair of your Xiaomi Mi 9

If you get stuck or have questions, you can post a comment. We’d be happy to help.

12 steps
  1. Switching off the Xiaomi Mi 9

    Xiaomi Mi 9 - Switching off the Xiaomi Mi 9 01
    Xiaomi Mi 9 - Switching off the Xiaomi Mi 9 02
    Xiaomi Mi 9 - Switching off the Xiaomi Mi 9 03
    1. Turn off your device by holding down the power button until the “Power off” option appears.
    2. Use your finger to confirm that you want to shut down your device and wait until the screen goes blank.
  2. Removing the back cover

    1. The back cover’s heavily glued to the chassis. Heat the device evenly with hot air to soften the glue. A temperature of 60 - 80°C should be sufficient. As a rule of thumb, you should still be able to touch your device without it being uncomfortably hot.
    2. The easiest way to loosen the back cover is to use a flat and flexible tool such as the iPlastix or iFlex. You will also need several picks to unstick the back cover all around.
    3. Heat the spot where you start and place a flat tool between the back cover and the frame.
    4. Use a suction cup to lift the glass if you can't find a place to insert your tool.
    5. With the iSclack, you can easily lift the back cover and then use a flat tool to loosen the glue. Put both suction cups on the display and the backcover and press the lever of the tool together like a pair of pliers.

    The iPlastix is made of plastic, so it won't scratch the device. On the other hand, it's very soft and tricky to insert. The iFlex makes it easier to get into the gap between the glass and the frame because it's made of very thin, stable metal. But it also makes it easier to scratch the frame of your device.

    Be extra careful, the back cover can break very easily. If necessary, apply the heat several times and try again. Removing the back cover might take half an hour. Take a little more time and work carefully to make sure you don't break anything.

    1. Once the tool is inserted, stick a pick into the gap to keep it open. Then run the tool around the entire edge to gradually loosen the glue.
    2. Then heat the next part and insert the picks one by one.
    3. Once the rear glass is unglued, you can lift it off.

    The covers of the cameras remain in the device and are not permanently attached to the back cover. Loosen the adhesive there as well and take care not to damage the flex cable of the covers.

  3. Removing the midframe

    Xiaomi Mi 9 - Removing the midframe 01
    Xiaomi Mi 9 - Removing the midframe 02
    Xiaomi Mi 9 - Removing the midframe 03
    Xiaomi Mi 9 - Removing the midframe 04
    • 10 × 3,1 mm Phillips
    1. Loosen the Phillips screws that secure the cover. The wireless charging coil and NFC antenna are attached to the plastic cover.

    One or more screws may be covered with a sticker. Remove the stickers or pierce them with a screwdriver.

    1. The cover is hooked into the housing. Lever with a tool under the plastic frame and lift the frame upwards.
    2. Now you can remove the plastic cover together with the coil.
  4. Disconnecting the battery

    Xiaomi Mi 9 - Disconnecting the battery 01
    Xiaomi Mi 9 - Disconnecting the battery 02
    Xiaomi Mi 9 - Disconnecting the battery 03
    • Battery connector
    1. Using the spudger, carefully disconnect the battery contact from the motherboard.

    Always lever from a side where there are no small components on the motherboard. This avoids unintentional damage to capacitors or ICs.

  5. Removing the speaker

    Xiaomi Mi 9 - Removing the speaker 01
    Xiaomi Mi 9 - Removing the speaker 02
    Xiaomi Mi 9 - Removing the speaker 03
    Xiaomi Mi 9 - Removing the speaker 04
    Xiaomi Mi 9 - Removing the speaker 05
    Xiaomi Mi 9 - Removing the speaker 06
    • 1 × 2,6 mm Phillips
    • 4 × 3,1 mm Phillips
    • 2 × 3,8 mm Phillips
    • Antenna connector
    1. Loosen the Phillips screws that secure the speaker.
    2. One of the screws is covered with a sticker. Remove the sticker first or pierce it with your screwdriver.

    The screws have different lengths. Be careful not to mix them up. The easiest way to do this is with an iDoc magnet mat. You can place the screws on it the way they are in the device and due to the magnetic adhesion the screws will not get lost.

    1. Then lever one side of the speaker with a spudger until it comes out of the device.
    2. There is one antenna connected on the back of the speaker.
    3. Loosen the antenna with a pair of tweezers by inserting them under the cable and then carefully lever it.
  6. Removing the battery

    Xiaomi Mi 9 - Removing the battery 01
    Xiaomi Mi 9 - Removing the battery 02
    Xiaomi Mi 9 - Removing the battery 03
    Xiaomi Mi 9 - Removing the battery 04
    Xiaomi Mi 9 - Removing the battery 05
    Xiaomi Mi 9 - Removing the battery 06
    Xiaomi Mi 9 - Removing the battery 07

    The battery in the Xiaomi Mi 9 is attached to the device with two adhesive strips. The adhesive strips have pull tabs, with which they can be easily loosened. This makes removing the battery quite comfortable and easy.

    1. First loosen the black tabs on the top of the battery.
    2. Now you have to pull out the adhesive strips very slowly. Keep the adhesive strips as flat as possible to prevent them from tearing.
    3. You can pull out the adhesive strips with your fingers and grab them repeatedly, or you can pull them out with tweezers and gradually wind them up.

    Hold the battery and the device firmly when pulling the last adhesive strip so that the battery cannot fall out of the device.

    If one of the adhesive strips tears, carefully lever out the battery with a wide spudger. Try to bend the battery as little as possible.

    1. If both adhesive strips are detached, you can remove the battery.
  7. The right tools for your repair

    With the right tools, you will succeed in any repair. In our store you will find a large selection of professional quality tools.
    VIEW NOW
  8. Installing the battery

    Xiaomi Mi 9 - Installing the battery 01
    Xiaomi Mi 9 - Installing the battery 02
    Xiaomi Mi 9 - Installing the battery 03
    Xiaomi Mi 9 - Installing the battery 04
    Xiaomi Mi 9 - Installing the battery 05
    Xiaomi Mi 9 - Installing the battery 06
    1. Apply new adhesive strips to the back of the battery so that it lies securely in the device and cannot move.
    2. You can use iPhone 5/5s adhesive strips and shorten them to fit the battery. This will allow you to conveniently remove the battery later.
    3. Alternatively, you can use very thin double-sided tape to glue in the battery.
    4. Apply the adhesive only to the marked areas.
    5. Then insert the battery into the display unit.
    6. Press the battery firmly into the housing so that the adhesive can adhere better.
  9. Installing the speaker

    Xiaomi Mi 9 - Installing the speaker 01
    Xiaomi Mi 9 - Installing the speaker 02
    Xiaomi Mi 9 - Installing the speaker 03
    • Antenna connector
    • 1 × 2,6 mm Phillips
    • 4 × 3,1 mm Phillips
    • 2 × 3,8 mm Phillips

    At the back of the loudspeaker an antenna has to be connected first.

    1. Put the speaker in position and connect the black antenna cable with a pair of tweezers and a spudger.
    2. Then reinsert the speaker over the USB port, press it tight and screw it into place.



    Make sure it sits flush at the bottom of the device.

  10. Connecting the battery

    Xiaomi Mi 9 - Connecting the battery 01
    Xiaomi Mi 9 - Connecting the battery 02
    Xiaomi Mi 9 - Connecting the battery 03
    • Battery Connector

    Reconnect the battery.

    1. Position the connector over its socket on the main board and press it down carefully.
  11. Installing the midframe

    Xiaomi Mi 9 - Installing the midframe 01
    Xiaomi Mi 9 - Installing the midframe 02
    Xiaomi Mi 9 - Installing the midframe 03
    • 10 × 3,1 mm Phillips
    1. Put the cover with the antenna back in the enclosure after hooking it onto the top of the enclosure.
    2. Then press the cover with your fingers until it clicks gently into place.
    3. Fasten the phillips screws.
  12. Testing the Xiaomi Mi 9

    Xiaomi Mi 9 - Testing the Xiaomi Mi 9 01
    Xiaomi Mi 9 - Testing the Xiaomi Mi 9 02
    Xiaomi Mi 9 - Testing the Xiaomi Mi 9 03
    Xiaomi Mi 9 - Testing the Xiaomi Mi 9 04
    1. Turn on your device and test it before you finally close it.
    2. Drag any app across the entire screen. Drag the app once around the entire border and then in a zigzag across the screen. The app should always follow your finger.
    3. Then test the display brightness by dragging the brightness slider to minimum and maximum.

    Test especially all functions of the part you replaced.

  13. Attaching the backcover

    Xiaomi Mi 9 - Attaching the backcover 01
    Xiaomi Mi 9 - Attaching the backcover 02
    Xiaomi Mi 9 - Attaching the backcover 03
    Xiaomi Mi 9 - Attaching the backcover 04
    Xiaomi Mi 9 - Attaching the backcover 05
    1. Check the adhesive on the edges of the back cover. If it's mostly intact, you can use it again and don't need any new glue.
    2. Make sure that the adhesive lies flat and does not wrinkle. If this is the case, warm it up a little and correct it with tweezers.

    Also check the adhesive around the camera cover and correct it if necessary.


    1. If the adhesive frame is too loose or does not stick properly, use new adhesive.
    2. To do this, first remove all old adhesive residues from the back cover. Use hot air again to loosen the glue more easily.
    3. Then apply the new adhesive frame or thin double-sided tape to reglue the backcover.
    4. Position the back cover over the device and press it down when it is exactly in the center.
    5. Heat the glue one last time and press the backcover on. You can weigh the device down with books or use clamps to compress the glue as long as it cools down (about 10-20min).
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