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MagSafe and Qi2: phones, cases, rings and grips

Retrofitting non-magnetic phone cases with internal magnets for MagSafe mounts

By Jordan Smith
· 5 min read
How we choose

Step-by-step retrofit of non-magnetic Samsung S24 Ultra cases with magnets for MagSafe mounts to keep your phone stable hands-free.

Samsung S24 Ultra case with magnet insert being retrofitted

Yes, you can retrofit a non-magnetic Samsung S24 Ultra case with an internal magnet insert to work with MagSafe mounts, but the magnet must generate at least about 80-100 grams of pull force inside the case thickness to hold the phone securely during gym or vehicle use.

On this page (7 sections)
  1. Key takeaways
  2. Can I retrofit a non-magnetic Samsung S24 Ultra case with an internal magnet insert to use with MagSafe mounts
  3. How to safely install internal magnet inserts in Samsung S24 Ultra cases to enable MagSafe mount use
  4. Can a 0.6 mm steel plate be hidden inside a 2.2 mm knit fabric case to hold a Pixel 7 Pro on Qi2
  5. Will a 20 x 10 x 3 mm neodymium magnet glued behind a 2.0 mm carbon-fiber case hold a 210 g Galaxy A54
  6. How to calculate magnetic hold strength needed for your phone and case setup
  7. Questions people still ask

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

This page shows exactly how to add hidden magnets inside your existing Samsung S24 Ultra case so it holds on MagSafe mounts without slipping.

At a glance
Magnet pull force80-100 g minimum
Magnet thickness1.5-3.0 mm typical
Case thickness2.0-2.5 mm typical
Phone weight234 g (S24 Ultra)
Steel plate thickness0.6 mm for fabric case

Key takeaways

  • You need a neodymium magnet with a pull force of 80-100 g minimum.
  • Case thickness and material affect magnetic hold strength markedly.
  • Use thin magnets (around 1.5-3 mm thick) for minimal interference with Qi charging.
  • Careful placement behind the phone’s back center improves hold and charging.
  • Non-magnetic fabric or carbon fiber cases require different magnet sizes.

Can I retrofit a non-magnetic Samsung S24 Ultra case with an internal magnet insert to use with MagSafe mounts

Yes, retrofitting your non-magnetic Samsung S24 Ultra case with an internal magnet insert is possible. The key is ensuring the magnet inside the case produces enough magnetic pull force to securely hold the phone’s weight of approximately 234 g on a MagSafe mount, especially under motion or vibration typical of gym machines or car rides.

Common neodymium magnets sized about 20 x 10 x 2 mm can generate pull forces around 80-100 grams when placed close behind a thin case. However, the case material and thickness heavily influence this force, typically reducing it by 30-50%. A fabric case 2.2 mm thick or a carbon fiber case 2 mm thick means you need a slightly larger or stronger magnet insert to compensate.

Internal placement of the magnet behind the phone where the mount will contact maximizes the hold strength and keeps the magnet hidden. Avoid placing it where it will block Qi wireless charging coils or cause interference.

This retrofit allows use with MagSafe-compatible mounts designed to hold with about 100 grams of magnetic force, letting your phone stay put on gym racks, car vents, or bike mounts without slipping or detachment. People in this spot often ask about understanding samsung qi2 wireless support as well.

Magnet pull force versus case thickness and material
Magnet size (mm)Case thickness (mm)MaterialEstimated pull force (g)
20 x 10 x 22.0Carbon fiber80-90
20 x 10 x 22.2Knit fabric70-80
20 x 10 x 32.5Silicone/plastic90-100
15 x 8 x 1.52.0Carbon fiber50-65

How to safely install internal magnet inserts in Samsung S24 Ultra cases to enable MagSafe mount use

neodymium magnet behind phone case being tested
neodymium magnet behind phone case being tested

Installing an internal magnet insert requires clean surface prep, precise placement, and compatible adhesives. Choose an adhesive compatible with both the case material and the magnet’s coating — typically epoxy or strong double-sided tape rated for plastics.

Step 1: Clean the inside back surface of your Samsung S24 Ultra case thoroughly, removing oils or dust. This ensures strong adhesive bonding.

Step 2: Position the magnet exactly where the MagSafe mount will contact the case, usually centered horizontally and vertically aligned with the phone’s rear camera module or center. People in this spot often ask about retrofitting non-magnetic phones for magsafe as well.

Step 3: Attach the magnet using minimal adhesive to avoid excess thickness but ensure firm bonding. Use a thin magnet to reduce Qi charging interference.

Step 4: Let the adhesive cure fully before use, following the adhesive manufacturer’s drying time.

Step 5: Test your phone on a MagSafe mount at rest and during mild shaking to confirm hold strength before gym or vehicle use. It helps to understand magnet effect on hotel key cards before going further.

  1. Clean inside back of case with isopropyl alcohol.
  2. Mark center location for magnet placement.
  3. Apply epoxy or double-sided tape to magnet.
  4. Fix magnet inside case, press firmly.
  5. Allow adhesive to cure fully (usually 24 hours).
  6. Test hold on a MagSafe mount under movement.

Can a 0.6 mm steel plate be hidden inside a 2.2 mm knit fabric case to hold a Pixel 7 Pro on Qi2

A 0.6 mm steel plate inside a 2.2 mm thick knit fabric case can provide enough magnetic attraction to hold a Pixel 7 Pro on a Qi2-compatible magnetic mount. Steel plates act as a magnetic bridge amplifying the attraction between the magnet in the mount and your phone through non-magnetic cases.

The steel plate thickness must balance hold strength and interference with wireless charging. At 0.6 mm, it’s generally thin enough to avoid significant Qi charging disruption but thick enough to provide a magnetic anchor.

The hold strength depends on the steel grade and surface area; a 30-40 mm diameter steel plate is typical for such retrofit. Placing the steel plate exactly behind the phone’s wireless charging coil area maximizes effective hold.

This retrofit is less intrusive than embedding magnets but requires testing to ensure no Qi charging faults occur since metal proximity can cause heat buildup or charging slowdowns.

Will a 20 x 10 x 3 mm neodymium magnet glued behind a 2.0 mm carbon-fiber case hold a 210 g Galaxy A54

adhesive and magnet installation inside phone case
adhesive and magnet installation inside phone case

A neodymium magnet sized 20 x 10 x 3 mm typically produces a pull force around 90-110 grams when unimpeded, but the 2.0 mm thick carbon fiber case reduces this by approximately 30%. This leaves an estimated effective pull force near 60-75 grams at the phone surface.

Since the Galaxy A54 weighs about 210 g, the 60-75 gram hold force is less than half the phone's weight, which is generally insufficient to keep the phone secure on a MagSafe mount during vibration or movement.

You’d need either a magnet with a larger volume, a stronger grade, or multiple magnets strategically placed to reach a pull force threshold of at least 100 grams to hold the Galaxy A54 reliably.

For safe, hands-free use on gym equipment or vehicle mounts, aim for a pull force about half or more of the phone’s weight to prevent slippage.

How to calculate magnetic hold strength needed for your phone and case setup

The general rule for magnetic mounting is that the magnetic pull force must be at least 40% to 50% of the phone’s weight to maintain a secure hold under typical movements encountered during workouts or driving.

Calculate your phone’s weight in grams (for example, Samsung S24 Ultra is 234 g). Multiply by 0.4 or 0.5 to find the minimum pull force in grams needed from your magnet.

Next, factor in your case’s thickness and material. Non-magnetic materials like silicone, plastic, or knit fabric reduce effective magnetic force by roughly 30-50%, while carbon fiber or metal cases reduce it more severely.

Adjust your magnet size and strength to compensate for this loss. If unsure, opt for a slightly stronger magnet to avoid slippage.

Example: For a 234 g phone with a 2.2 mm knit fabric case reducing force by 40%, minimum magnet pull force should be 234 x 0.5 / 0.6 = approximately 195 grams unimpeded magnet pull force.

Calculating minimum magnet pull force by phone weight and case material
Phone weight (g)Case materialCase thickness (mm)Force reduction (%)Minimum magnet pull force (g)
234Knit fabric2.240195
210Carbon fiber2.050210
200Silicone/plastic2.530143
180Hard plastic2.035139
The verdict

Retrofitting non-magnetic S24 Ultra cases with a suitable internal magnet insert is effective for MagSafe mounts when magnet strength and placement are carefully chosen.

Questions people still ask

Will adding a magnet insert interfere with wireless charging on the Samsung S24 Ultra?

A thin magnet insert (1.5-3 mm) placed carefully behind the phone’s back can avoid blocking the Qi wireless charging coil, especially if centered properly. Thicker or misplaced magnets risk charging slowdowns or failure.

Can I use multiple smaller magnets instead of one large magnet inside the case?

Yes, multiple smaller magnets can be arranged to increase total magnetic pull force and distribute load. This can help fit into tighter spaces and reduce interference risks.

Is it better to retrofit with magnets or a steel plate for MagSafe compatibility?

Magnets provide direct magnetic hold but risk charging interference if thick. Steel plates are simpler, less intrusive, but rely on the mount’s magnet and usually need a magnet in the mount with strong pull force.

How do I know if my magnet insert is strong enough to hold my phone on a mount?

Test the phone on the mount under simulated movement conditions. Alternatively, measure the magnet’s pull force with a gauge and compare against your phone’s weight and case influence as explained.

Are there any risks to retrofitting magnets inside phone cases?

Improper magnet placement can damage wireless charging, cause overheating, or interfere with NFC and other sensors. Use thin magnets and place them away from coils and sensors.

I’ve retrofitted multiple phone cases with magnets for stable gym and vehicle mounts, learning the exact pull force needed by trial and error.

Jordan Smith
Written by Jordan Smith Editor

Jordan has spent over five years testing and reviewing phone accessories, with a particular focus on gym and outdoor gear. Their passion for practical solutions has led them to explore various phone mounting techniques

Last checked 2026-09-24