Placing your credit card too close to even a moderately powerful magnet could demagnetize the card and render it unusable. The question then arises whether magnets can have a similarly devastating effect on cellphones.
Are Magnets Safe With Smartphones?
Magnets do have the potential to damage a broad range of electronics. For example, they can erase VHS tapes and floppy disks because the data is being recorded magnetically. It is "theoretically possible" to corrupt a hard drive if an "incredibly strong magnet" is run "directly over the surface" of the drive, according to expert Matt Newby.
Smartphones and similar mobile devices do not use storage media that records data magnetically. Smartphones generally use flash storage, and this type of storage media is "not really affected by a strong, static magnetic field," says K&J engineer Michael Paul.
Generally, everyday consumer magnets are perfectly safe for your cellphone and will not cause any major harm to the device. Most smartphone screens use LCD (liquid crystal display) or AMOLED (active-matrix organic light-emitting diode) technology. In both cases, the mechanism is controlled by electricity and is unaffected by magnets.
Similarly, while magnets can theoretically impact the speakers and the reception on your cellphone, the impact of minor magnetic fields on these components is largely negligible. Contactless payment systems, like Google Wallet and Apple Pay, use near field communication (NFC) technology which is not impacted by magnetic fields.
Cellphone Accessories With Magnets
While it is unlikely your cellphone will come in close contact with extra powerful electromagnets or other industrial strength magnets, a great number of mobile accessories do use magnets as part of their design.
Mounts and Cases
Several cellphone car mounts utilize a magnetic design to hold the phone in place. This magnet is typically placed on the back of the cellphone, sometimes behind or as part of the cellphone case.
Certain wallet style cases for smartphones also feature a magnetic clasp to help keep the case closed. The magnets used in these car mounts and wallet cases are generally not very powerful and should not have a dramatically detrimental effect on your mobile device.
Made for iPhone
If you have an iPhone and would like to have greater assurance about the potential impact of magnets in your accessories, look for products with the "Made for iPhone" designation. Apple lays out a strict set of rules and guidelines for manufacturers to follow, but if there is any damage as a result of using them, products with this designation are generally covered under AppleCare if you have a protection plan.
Even though the risk of harm to your cellphone is relatively minimal, there are areas where magnets may have a potentially negative impact on your cellphone. Magnets may:
- Interfere with the internal digital compass of the phone, requiring compass recalibration
- Magnetize some internal steel components slightly, transforming them into weak magnets that then interfere with the compass for calibration
- Affect the autofocus and optical image stabilization in some smartphone cameras
- Force the battery to work harder to supply the right voltage if placed in a very strong magnetic field
You are surrounded by magnets and magnetic fields all the time. Electric cars generate a magnetic field, but they "pose no danger to drivers or passengers." A variety of household appliances, like vacuum cleaners and microwave ovens, also generate electromagnetic fields. Unless your cellphone is in the presence of very powerful, industrial magnets, your phone likely will not experience any major effects.