Galaxy S21 5G - Replacing the battery

Use our checklist to test the basic functions of your Galaxy S21 5G before repairing. This way you can check afterwards if your repair was successful.

1. Press and hold the side and volume down button simultaneously for a few seconds.
2. Tap Power off in the displayed menu and confirm with your unlock code.

The edge of the back cover is heavily glued. It is therefore essential to first heat it up sufficiently. Use a hot air device for this purpose, such as a heat gun or an ordinary hair dryer.

1. Heat the edge of the back cover by running the hot air device evenly over it.

To create a narrow gap between back cover and display unit you need a flat, stable tool. We recommend the iFlex for this, since it has particularly sharp edges that can be easily inserted.

1. Attach a suction cup to the lower edge of the back cover and pull it upwards. Insert the iFlex between the display unit and the back cover at the same time.

To avoid damaging the edge of the case with the sharp edges of the iFlex, you should switch to a plastic tool like the iPlastix as soon as possible.

To avoid damaging the camera module, you should not insert your tool too far into the device. We recommend the hard plastic pick at this point. Due to its shape it cannot be inserted too deeply.

1. Drive the tool completely around the edge of the back cover to loosen it piece by piece.
2. Slide flat picks under the back cover at regular intervals, so that the glue cannot bond again.

1. Once the back cover is completely detached, you first have to remove all plastic picks.
2. Then unfold it and put it aside.

• 5 × 4.9 mm Phillips

Use a screw storage to keep an overview during the repair and avoid losing anything. Use an old sewing box, for example. With our high-quality magnetic pad, you have the additional advantage that nothing slips.

1. Loosen the five Phillips screws from the charging coil cover.
2. Then put them on your magnetic pad.

• Connector

Always detach the battery connector as soon as possible to avoid a potential short circuit.

When separating connectors, always start from the side where there are no small components on the motherboard. This way you avoid potential damage.

1. Lift up the metal cover of the NFC antenna.
2. Carefully pry the orange battery connector underneath from the motherboard with a plastic lever tool. We use a plastic spudger for this.

• Connector

1. Then separate the black connector of the charging coil by carefully levering it off the circuit board with a spudger as well.

The lower end of the charging coil is slightly glued.

1. Once the connectors are separated, you can carefully pull off the charging coil.

• 6 × 4.9 mm Phillips

1. Remove the six Phillips screws from the speaker module.
2. Then place them on the magnetic pad.

A small arrow in the upper left corner shows you where to place your tool.

1. Carefully lever the speaker module out of its guide and put it aside.

• Connector

1. Separate the connectors of the two connecting cables from the USB and motherboard each.
2. Then remove the detached cables from your device.

• Connector

The screen cable is attached to a separate slot for the first time in the Galaxy S21, so it can be removed completely.

1. Use a spudger to carefully lever the connectors of the screen cable off the USB and motherboard respectively.

1. Remove the detached display cable from the device.

The battery of the S21 5G is heavily glued into the display unit. In order to make it easier to remove, you should therefore heat it previously.

Never heat the sensitive battery directly, but only from the display side.

1. Heat the battery by running a hot air gun evenly over the corresponding opposite spot on the display.

Once the adhesive has warmed up sufficiently, the easiest way to lift the battery is to use a suction cup and a plastic lever tool.

1. Place the suction cup on the lower edge of the battery and pull it upwards to lift the battery up.
2. At the same time, use a plastic lever tool on the lower edge of the battery to push the battery upwards. We use the battery spudger for this purpose.

The battery can be loosened particularly well if you move the iPlastix under the battery with a knife movement.

You can insert a flat pick to prevent the adhesive from bonding again at a point that has already been loosened.

1. Insert the flat iPlastix at the lifted edge and slide it under the battery bit by bit to completely detach it from the bottom of the screen unit.

1. Take the detached battery out of the device and put it aside.

You may have to bend the connector of the replacement battery to ensure that it can be properly attached. Align it with the help of the connector slot of on the motherboard.

1. Carefully bend the connector of the replacement battery before installing it.
2. Then remove the protective foils from the battery's front and back.

1. Insert the replacement battery into the display unit and press it firmly.

• Connector

The label on the screen cable will help you to align it.

1. Align the display cable and press the two connectors respectively onto the motherboard and the separate slot. You should hear and feel them click into place.

• Connector

The label on the screen cable will help you to align it.

1. Position the two connecting cables in the device again.
2. Attach their two connectors to the motherboard and USB board respectively.

The speaker module has three small lugs. To ensure that the module sits evenly in the device, these must be hooked into the frame of the screen unit when inserting it.

1. Put the speaker back in its original position.

• 6 × 4.9 mm Phillips

When screwing components into place, make sure that you do not mix up the screws. A too long screw in the wrong place could damage the display in the worst case.

1. Screw the speaker module in place with the six Phillips screws.

1. Reposition the NFC antenna in the screen unit and press its back end slightly to allow the glue to bond again.

• Connector

1. Lift up the metal cover of the charging coil to attach its black connector that is located underneath.

Always connect the battery connector last to avoid a potential short circuit.

1. You can now also reattach the orange battery connector to the motherboard.

• 5 × 4.9 mm Phillips

1. Once the battery and charging coil are reconnected, you can screw the metal cover back on.

If something doesn't work properly during testing, double-check that everything is installed and attached correctly.

1. Connect your Galaxy to the mains in order to check the functionality of the replacement battery.
2. Also place it on a wireless charger, if available, to check the wireless charging function.
3. Call up the Samsung test menu via *#0*# in the phone app to test additional components. As an alternative use our checklist.

Attaching a new adhesive frame is optional. If it is still in good condition, you do not need to install a new one. However, if it has defects or no longer sticks properly, we recommend that you install a new adhesive frame.

1. We show you how to apply a new adhesive frame in detail in our YouTube video.

We recommend that you run hot air over the edge of the back cover again, so that the glue bonds properly. You can also weigh down your device with books for a few minutes or clamp it like in our example.

1. Close your Galaxy S21 5G after the repair by pressing the back cover back onto the display unit.