Case thickness limits for MagSafe and Qi2 charging with magnets and inserts

Part of our guide on compatibility of magsafe mounts

This page explains how to measure and test whether your case, magnets, and wallet inserts will interfere with MagSafe or Qi2 charging, gives practical observed ranges rather than invented absolutes, and points to official sources and testing approaches you can use for your exact phone and chargers.

How to interpret numeric thresholds and why no single cutoff exists

Apple’s MagSafe, Google’s Pixel/Pixel Stand guidance, and the Wireless Power Consortium (WPC) Qi/Qi2 documents do not publish a single universal millimetre measurement that guarantees or forbids charging through a particular thickness or magnet arrangement.

Instead, they define interface behavior, alignment and safety requirements, and allowable magnetic fields in broader terms. That leaves practical limits to be determined by testing and by the interaction of three things: physical spacing (the sum of all layers between transmitter and receiver coils), the magnetic field strength and geometry of any magnets, and the coil and recognition logic of the charger.

Measured guidance: practical ranges and what they mean (approximate, experiential)

Across published lab tests and user reports, reliable MagSafe attachment and Qi2 charging are commonly reported when the total spacing at the charging area is within roughly 2–4 mm. As spacing increases beyond that, reliability and charging speed frequently decrease.

At spacings in the mid‑range (around 4–6 mm), behavior becomes model‑dependent: some phone + charger combinations will still work intermittently, while others will stop working. Above roughly 6 mm total spacing, most chargers — particularly public Qi2 pads — are unlikely to charge consistently. These figures reflect observed behavior across many setups; they are not a guaranteed limit. The other half of this decision is preventing camera app errors from magnets.

How magnets and magnetic wallet inserts change the picture

Magnets affect charging in two ways: they change the net magnetic field used for magnetic attachment and can interfere electrically with inductive coupling. Unshielded neodymium magnets placed directly over the charging coil are the most disruptive because they create a strong, localized field that can misalign the charger and device or trigger the charger’s foreign object detection (FOD) and safety logic.

Wallet inserts that are ferrite‑shielded are designed to keep magnetic fields directed away from the coil area and reduce interference; these are far more likely to remain compatible at a given thickness than unshielded magnets. A thin ferrite‑shielded insert of a few millimetres is often acceptable, while an unshielded neodymium puck of similar thickness may stop charging or cause the charger to emit an error.

How charger and phone model change outcomes

Different chargers have different transmitter power, coil size, and foreign object detection logic; phones have different receiver coil locations, sizes, and firmware. For example, some proprietary chargers with dedicated alignment magnets (or mechanical guides) may maintain charging where a public Qi2 pad fails. If that sounds like your situation, read up on influence of magnets on mount grip next.

Phone designs also matter: some phones have larger or multiple coils that tolerate misalignment better, while others rely on a small central coil and precise alignment. Manufacturers rarely publish the exact coil geometry or the maximum allowable air gap, so model‑to‑model testing is essential. If you rely on public chargers frequently, prioritize testing with those exact chargers; if you mostly use a single known dock (for example, an official MagSafe charger designed for a specific iPhone model), expect better tolerance in that specific pairing.

How to measure and test your case + magnet setup (practical steps)

1) Identify the charging coil area on your phone. For most phones, this is centered on the back; manufacturer teardowns or alignment marks in official accessories can help.

2) Measure thickness: use calipers or a ruler to measure the case thickness at the coil location, then add the thickness of any magnet rings or wallet inserts that sit over the same area. Record the total spacing in millimetres. There is more on estimating magnet force for magsafe mounts in a separate guide.

3) Note magnet type and placement: mark whether the magnet is ferrite‑shielded or unshielded neodymium, its approximate diameter, and its grade if known (e.g., N42, N52).

4) Test with chargers: try your intended proprietary charger (e.g., an official MagSafe puck), then try representative public Qi2 pads you use. Observe whether the device starts charging, how quickly it does so, whether charging stops/starts, and any heat or error signals.

5) If charging is unreliable, remove or thin the insert, or switch to shielded inserts or different case solutions.

at what case thickness will magsafe attachment and charging fail (and how do magnetic wallets/inserts affect qi/qi2)

Comparison of typical zones and magnet types helps clarify likely outcomes. Use this table as a practical guide — always measure at the coil and test with your charger and phone.

References and further reading (official documentation and credible third‑party tests)

- Apple: MagSafe for iPhone — Apple’s support and developer pages describe MagSafe accessory design and alignment behavior but do not publish a single mm cutoff. See Apple MagSafe developer documentation and the MagSafe accessory guidelines for recommended alignment and magnet field considerations: https://developer.apple.com/magsafe/ and https://support.apple.com/ (search “MagSafe” on Apple Support).

- Wireless Power Consortium (WPC) / Qi2: WPC publishes Qi/Qi2 specifications covering coil alignment, safety, and foreign object detection. The publicly available documents set interoperability and safety requirements but characterise allowable gaps and magnetic field interactions in engineering terms rather than a single phone‑agnostic mm threshold. See https://www.wirelesspowerconsortium.com/ (search Qi2 specification and developer resources).

- Google Pixel support: Google’s Pixel wireless charging pages outline compatible accessories and include notes on wireless charging behaviour; they do not provide a single mm limit. See https://support.google.com/pixelphone/ (search wireless charging).

- Technical teardown and test reports: independent labs and reviewers (e.g., ChargerLAB, iFixit teardown notes, and major tech reviewers) publish measured tests showing how coil coupling and charging power drop with increased spacing and with magnets. These sources illustrate the empirical ranges described above; search for “MagSafe case thickness test” or “Qi charging distance test” for examples.

- Academic and engineering resources: textbooks and papers on inductive coupling explain why coupling falls off quickly with air gap and how external magnetic materials affect mutual inductance — useful for deeper understanding.

Questions people still ask

This article consolidates manufacturer guidance (MagSafe and Qi2 documents) and a wide set of published third‑party tests and user reports into practical measurement and testing advice. All numeric figures are presented as observed ranges and guidelines, not absolute limits.