Battery replacement of Samsung Galaxy S21

• Unplug any cables from your Samsung and turn off the phone

• A) Heating the bottom edge
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• It is recommended to wear protective ESD gloves.
• Using a hair dryer or heat gun, heat the bottom edge of back cover for about 2 minutes to reach a temperature of approximately 80°C (176°F), or until it becomes difficult to keep your hand on the cover due to the high temperature.
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• Heating the cover helps to soften the adhesive between the rear housing and the phone frame, making it easier to open.
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• B) Opening the rear housing
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• The cover can be separated in two different ways: The first method is using a suction cup, and the second method is using a securing tool, which is safer.
• In this guide, we will proceed using a suction cup.
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• Placement of the suction cup
• Place the suction cup near the bottom edge of the back cover in the center.
• After separating the rear housing about 3 mm from the frame, insert a pick or card into the gap.
• (How tight the adhesive holds depends on the age of your phone so if you cant separate the back cover from the frame try reheating the adhesive that holds the cover and pull again.)
• Remember to insert the pick or card only 5 mm in so you don’t do any damage to internal components.
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• C) Separate the bottom edge with opening tool
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• Move the pick or card alongside the bottom edge so you separate the adhesive. Leave the pick in so it stops adhesive from resealing.
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• D) Separating the adhesive (left side of the phone)
• Heat the left side of rear cover with the tool you used before and after 3 minutes or heating it to the right temperature (so hot you can’t put your hand on it) move the suction cup in the center of the left side of rear housing then pull with steady force and slide the pick or card from the cameras to the bottom left corner, separating the adhesive.
• If you can, leave the pick in to stop the adhesive from resealing.
• Warning: Do not slide the opening tool in the camera shell, you can crack it.
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• E) Heating the right edge
• Using a heat gun or a hair dryer, apply heat to the right side of the phone for 3 minutes or until the side becomes too hot to touch.
• Move the suction cup to the middle of the right side. Pull it with the steady force till you create a gap in the cover and frame so you can slide the pick in.
• Warning: Insert the pick in only about 3mm on this side as you may damage the cable that runs parallel with the right edge.
• Slide the pick or card around the top right corner of the phone to separate the top adhesive.
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• F) Separating the adhesive (righ side of the iPhone)
• Carefully slide an opening pick into the gap you created.
• Ensure that the pick is inserted no more than 3 mm to avoid potential harm to the secondary interconnect cable, which is positioned parallel to the right edge.
• Move an opening pick in a back-and-forth motion along the right edge of the back cover to sever the adhesive.
• Once completed, keep the pick in place to prevent the adhesive from resealing.

Using a heat gun or a hair dryer, apply heat to the top side of the phone for 3 minutes or until the side becomes too hot to touch.

Twist the opening pick along the upper-right corner of the phone, focusing on the right edge.

Ensure the pick is inserted no more than 5 mm to avoid potential harm to internal components.

Repeat this process for each corner, excluding the top-left corner where the rear-facing camera is situated.

Slide the opening picks nearest to the top of the phone towards the camera housing, aiming for close proximity.

Repeat this action with the pick positioned along the left edge of the device.

Using a heat gun or a hair dryer, apply heat around the camera shell for 3 minutes or until it becomes too hot to touch.

Turn the back cover counterclockwise to generate space between the camera shell and the frame.

Ensure the pick is inserted no deeper than 5 mm to prevent any potential scratches to the camera.

Slide an opening pick into the gap.

If this approach proves ineffective. Here is an alternative method.

Carefully maneuver the two picks towards the camera shell until they sit beneath the corners of the back cover adjacent to the camera housing.

Slide the picks back and forth along the bridge connecting the back cover and the camera shell until a gap forms between the camera shell and the frame.

Exercise caution during this process to avoid the potential of cracking the plastic back cover.

Insert an opening pick between the camera shell and the frame to separate the adhesive.

Due to the substantial amount of adhesive securing the frame to the camera shell, it may be necessary to apply heat multiple times to facilitate the process.

There is extra adhesive located to the right of the camera that requires cutting through.

Please note that there is a plate on the back cover surrounding the phone's flash which the pick may potentially get stuck on:

Ensure to angle the pick downward to prevent any damage.

Align the tip of the opening pick with the flash of your phone.

Carefully insert the pick, ensuring it avoids contact with the flash's plate.

Take note that the resistance from the plate may resemble that of adhesive. Keep the pick angled downward to prevent it from inadvertently sliding into the plate.

Proceed to slice through the adhesive located to the right of the camera.

Take off the back cover.

If the back cover remains attached to the frame, slide the pick along the phone's edges until the back cover fully detaches.

When reassembling:

This marks a suitable moment to switch on your phone and assess all functions before sealing it shut. Ensure to power off your phone entirely before continuing your work.

Eliminate any remaining adhesive remnants using tweezers or your fingertips. Employ high-concentration (over 90%) isopropyl alcohol to clean off any adhesive residue.

Utilize a Phillips screwdriver to take out the five 4 mm screws that hold the motherboard bracket to the frame.

During this repair, keep track of every screw and ensure each one is returned to its original position.

Use a pair of tweezers to gently lift and release the motherboard bracket from the frame.

Do not fully detach the bracket yet, as it's still connected to the wireless charging coil.

While using tweezers or your fingers to keep the motherboard bracket aside, use a spudger to lift the battery press connector.

Be careful to lift only under the edge of the connector to avoid damaging the socket or nearby components.

When reattaching press connectors of this type, align them carefully and press down on one side until it clicks into place, then do the same on the other side. Avoid pressing in the center. Misalignment can bend the pins, causing irreversible damage.

While keeping the motherboard bracket out of the way, use a spudger to lift and disconnect the press connector for the wireless charging coil.

It is lightly adhered to the phone.

Gently peel the wireless charging coil away from the phone using your fingers.

When reassembling.

First secure the motherboard bracket screws to properly align the charging coil, then firmly press the rest of the coil down to ensure it adheres properly.

Use a Phillips screwdriver to remove the six 4 mm screws securing the loudspeaker to the frame.

Insert the tip of a spudger into the notch in the top-left corner of the loudspeaker and pry upwards to release the clips securing it.

Take out the loudspeaker.

Use the flat end of a spudger to lift and disconnect the press connectors for the primary interconnect cable.

Use the flat end of a spudger to lift and disconnect the press connector for the secondary interconnect cable

Use tweezers or your fingers to carefully take out both the secondary and primary interconnect cables.

Use a spudger to lift and disconnect the bottom and top press connectors of the display cables.

Using tweezers, or your fingers remove the display cable.

Avoid puncturing or bending the battery during removal, as it can leak dangerous chemicals or cause a thermal event. If you have difficulty removing the battery, apply more isopropyl alcohol and try again.

Place a few drops of high-concentration (over 90%) isopropyl alcohol around the gaps surrounding the battery's perimeter.

Start with only a few drops and add more if needed; excessive isopropyl alcohol could spill onto the motherboard and daughterboard.

Attach a suction cup to the battery near the center of the right edge.

Insert an opening pick into the edge with the largest gap between the frame and the battery.

Rotate the pick to insert its long edge into the gap.

Pull up on the suction cup with steady, firm pressure while using the opening pick to pry the battery away from the frame.

If you find it difficult to lift the battery with the suction handle, add a few more drops of isopropyl alcohol and try again.

Ensure that any leftover adhesive is peeled off. Do not reinstall a damaged or deformed battery, as it poses a safety risk.

Secure the new battery using pre-cut adhesive or double-sided tape.

Apply the new adhesive to the device where the old adhesive was, not directly on the battery, and press the battery firmly into place.

During reassembly, temporarily reconnect the battery to the motherboard for alignment, then disconnect it once positioned.

If any alcohol remains, clean it with a lint-free cloth or allow it to dry before installing the new battery.

Remove all the battery cover adhesive around the back frame of your device. Using a spudger or tweezers.

Be sure to remove any remaining smaller bits of adhesive with the tip of your spudger.

Be careful not to damage any of the spring contacts as you go around the frame.

• Using a lint-free cloth (or coffee filter) with a bit of isopropyl alcohol, clean the areas of the frame and display where you removed the old adhesive.

This will help remove any remaining adhesive residue and prep the surface for the new adhesive.

For best results, swipe your cleaning cloth in one direction, not back and forth.

Apply new adhesive around the back edges of the phone, also place a new adhesive around the camera.

 Reconnect all the components of the display assembly through a reverse process.

The new adhesive will ensure the resistance to water and dust.

Be precise while applying the new adhesive. Improper installation could lead to your phone not being water-resistant, and there's a higher likelihood of dust or moisture ingress.

• After placing the new battery in place you can start reassembling the Samsung
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• Also check the phone for excess screws and small parts that may be stuck in the body of phone and remove them.
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• When reassembling the phone back to its original state, follow these instructions in reverse order.
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• After reassembly, perform a forced restart. This may help prevent any possible issues.