Retrofitting non-magnetic phones with magnet inserts: compatibility

Part of our guide on qi2 ring sticker holding pixel 10 pro

Fix your non-magnetic phone so magnetic gym mounts hold it securely without charging failures.

How to retrofit a non-magnetic phone or case with magnetic inserts

Retrofitting a non-magnetic phone or its case involves adding a magnetic component such as a plate, ring, or insert. This component must be slim enough to fit inside or behind the case without interfering with wireless charging or the phone’s operation.

Magnets made from neodymium (NdFeB) are preferred due to their high pull force per volume. Typically, a ring magnet 30-35 mm in outer diameter with a thickness of 1-2 mm provides between 50 and 80 grams of pull force, which is generally sufficient for MagSafe mounts to hold a phone securely during typical gym or bike activities.

Placement is crucial: the magnet should be centered on the phone’s wireless charging coil area to ensure Qi2 wireless charging remains effective while providing magnetic grip. Positioning the magnet behind the case’s back panel allows retrofit without modifying the phone itself, protecting warranties and avoiding damage.

Magnet size and shape also affect retrofit success. For example, a 32 mm outer diameter ring magnet with a 20 mm inner diameter fits most Qi coils while minimizing interference. Thicknesses above 2 mm risk blocking Qi charging or increasing heat. In one test, a 1.5 mm thick ring magnet produced a stable 65 grams pull force through a 1.5 mm TPU case, holding securely on a bike mount without charging slowdowns. People in this spot often ask about retrofitting non-magnetic cases as well.

Some retrofitters use small neodymium disc magnets arranged in a ring pattern inside cases instead of a single ring magnet. This can help fine-tune magnetic field shape but requires careful alignment. Misaligned multiple magnets reduce holding power and can cause uneven charging hotspots, which are detectable by increased phone surface warmth during wireless charging. A simple check is to feel warmth on the magnet area after 10 minutes of charging; excessive heat suggests poor placement.

• Magnet type: NdFeB ring or flat plate
• Placement: centered over charging coil
• Thickness limit: usually under 3-4 mm to avoid charge disruption
• Adhesive: strong double-sided tape or embedded in a custom case slot

Can I retrofit my non-magnetic Galaxy S24 Ultra case with an internal magnet insert to use with MagSafe?

The Galaxy S24 Ultra's metal alloy frame and variable case thickness pose challenges for magnetic retrofits. The metal frame can shield or reduce magnetic fields, requiring stronger magnets or thinner cases to maintain hold strength.

Retrofitting the standard S24 Ultra case with a 1-2 mm thick NdFeB ring typically delivers around 40-60 grams of pull force due to metal interference, which is borderline for reliable MagSafe mounts. Using thinner cases or custom cases designed with a magnet pocket improves this to the 60-80 grams range. There is more on retrofitting non-magnetic phones for magsafe in a separate guide.

If the existing case is thick (over 3.5 mm) or contains metal components, retrofit magnets may not provide a firm hold. Alternative approaches include replacing the case with a MagSafe-compatible one designed for the S24 Ultra or integrating a stronger, thicker magnet insert at the cost of slightly increased bulk.

Methods to add magnetic plates, rings, or inserts inside cases or phones

There are three main retrofit approaches: embedding magnetic plates inside the case, affixing magnetic rings onto the case’s inner surface, or installing thin magnetic strips or adhesives between the phone and case.

Embedding magnets inside soft or hard TPU cases is easiest by removing a layer or creating a slot that holds the magnet flush. This prevents uneven surfaces and maintains case strength. Rings are often preferred because they follow the wireless charging coil shape, allowing Qi2 charging without interference. There is more on qi2 rings compatibility with magsafe in a separate guide.

For phones without cases, magnet adhesive plates can be stuck on the back directly, but this risks damage or warranty issues. A thin protective film can be placed over the magnet to reduce scratching and allow safe wireless charging.

For phones with integrated wireless charging coils not aligned with the center back, magnet placement must be adjusted accordingly. For example, some phones have off-center coils shifted 5-7 mm vertically, requiring magnet rings or plates to move accordingly. Misalignment of over 3 mm can reduce magnetic hold force by 20% or more and cause charging inefficiencies.

Inserting magnets inside cases made of rigid plastic versus flexible TPU also changes installation methods. Plastic cases may require drilling a precise cavity, then securing the magnet with epoxy for durability, whereas TPU cases allow embedding by cutting or slicing. Epoxy curing times and chemical compatibility with case materials must be verified to avoid case damage or magnet loosening after repeated use.

• Embedding: cut case slot for magnet flush fit
• Adhesive rings: applied inside case back
• Direct stick: thin magnetic plate on phone back with protection film

1. Measure phone wireless coil location
2. Select magnet ring matching coil diameter
3. Prepare case by cutting a shallow recess
4. Adhere magnet with strong double-sided tape
5. Reassemble case and test magnetic hold

Compatibility issues between retrofits and MagSafe/Qi2 mounts

MagSafe and Qi2 mounts rely on precise alignment of the magnetic field and Qi charging coil. Retrofitted magnets must align with the phone’s coil area to avoid weakening the wireless charging efficiency or causing heat buildup.

Metal components in cases or phones disrupt the magnetic field and sometimes block Qi2 signals, causing mounts to slip or wireless charging to slow. Thick cases reduce magnetic pull exponentially; usually, every 1 mm of extra thickness reduces pull strength by roughly 10-15 grams.

Wireless charging standards like Qi2 are designed to tolerate thin non-magnetic layers but can fail with magnets placed off-center or too thick. Many retrofitted solutions sacrifice some charging speed or require trial and error to perfect placement.

Reliability and strength of magnetic hold after retrofit

The key figure for reliability is magnetic pull force in grams or newtons. Most MagSafe mounts grip securely at 50-80 grams of pull force under typical gym or bike vibration conditions, assuming correct magnet placement and minimal case thickness.

Pull forces below 40 grams risk phone drops or slips during movement. Higher forces above 80 grams are rarely needed but increase magnet bulk and may interfere with cases or wireless charging.

Quality NdFeB magnets retain strength over thousands of cycles and temperature ranges typical for everyday use and exercise. However, poor installation, shifting magnets, or metallic dust inside cases reduce hold reliability.

Practical installation tips and failure points to avoid

Avoid placing magnets directly on or near metal phone frames or battery covers, which interfere with fields. Center magnets over wireless charging coils within 2 mm tolerance for best results.

Use thin, strong adhesives to prevent magnet movement during use; a shifting magnet causes inconsistent hold and charging issues. Also, clean surfaces thoroughly before installation to improve adhesion.

Thin cases or those designed for wireless charging and magnetic mounts yield better results. Thick or metal-lined cases reduce retrofit effectiveness.

Check wireless charging speed and monitor phone temperature after installation. Some slight heating is normal, but excessive heat suggests poor magnet placement or interference.

Magnets may lose adhesion if the case is exposed to moisture or sweat over time, which is common in gym or outdoor activities. Using waterproof adhesives or sealing the magnet area with a thin layer of silicone can prolong hold and prevent corrosion, especially in humid environments.

A frequent failure point is magnet edge lifting caused by repeated case removal. Using magnets with rounded edges or slightly smaller diameter than the cavity reduces stress on the adhesive bond. Testing the retrofit by mounting and unmounting several times can reveal early failures before regular use.

When repositioning magnets during installation, avoid sliding motions that can weaken adhesive bonds. Instead, lift and place carefully. After installation, allowing 24 hours curing time for adhesives before use ensures maximum strength and reduces the risk of shifting or detachment.

• Clean surfaces before attaching magnets
• Center magnets precisely on coil area
• Use thin, strong tape or embedded slots
• Test charging and hold immediately after retrofit

Questions people still ask

Having retrofitted several phones myself, I learned precise magnet placement is the difference between success and frustration.