Will Wireless Phone Chargers Damage Credit Cards? (ANSWERED)

Wireless phone chargers stations use magnetic induction – the ability of a magnetic field to create current inside a conductor — to power your phone’s battery without plugging directly into a cable. 

This is extremely convenient for our ‘get up and go’ lifestyles but does it hold any risks – specifically to your banking cards should you store them in a card carrying phone case?

Cell phone and wireless charging manufacturers will warn against leaving credit cards with a readable magnetic strip in the wallet area of your phone case when wirelessly charging. This is because the magnetic fields generated by the coils in your charger and phone have the potential to  alter iron particles in the magstripe on a card that are used to hold data.

EMV chips used to make your card more secure, as well as RFID chips that enable contactless payments are not affected by magnets and so are at no risk of being damaged. 

Despite the industry warnings however, our own tests demonstrate that the likelihood of your cards becoming unusable due to being exposed to wireless chargers are slim to none!

This post has been laid out to explain why these opinions conflict, whilst sharing the safest way for you and your banking cards to continue charging wirelessly. 

Image by towfiqu ahamed on Canva Pro

Are wireless phone chargers safe to use around credit cards?

Using a wireless charger to charge your smartphone’s battery could in theory damage the magnetic strip on your banking card, credit card or identification should they be placed between the phone and charger pad. 

This is because the iron based particles that hold data (such as name, address, account number etc.), and makes a credit card readable when swiped can be permanently altered from their original north or south pole direction when exposed to a magnet – or a strong electromagnetic field.

And when it comes to wireless charging, which is based on the basic principle of transferring energies between two coils (sound a bit Nikola Tesla-y? It should!).

The coil within the wireless charging station has to be connected to an outside power source for it to begin creating an electromagnetic field that contains an alternating current (AC).

When the second coil (like the one found inside your smartphone) enters the electromagnetic field, the circuit is completed and converted into a direct current (DC), thus charging the battery of your phone.

Samsung and Apple (who at the same time are happy to sell the MagSafe wallet designed to fit onto the back of your iPhone) certainly think this electromagnetic threat is a concern to be heeded. 

As demonstrated by YouTube Channel Supermagnete, direct contact with a powerful magnet immediately damages even the high quality magnetic strips on a credit card.

However we couldn’t find any conclusive evidence of whether exposure to weaker magnetic fields such as those generated by wireless chargers could result in the same damage being sustained. 

The only way to truly test whether wireless chargers damage credit cards was to conduct an experiment ourselves. 

One of our own credit cards (that lacked an RFID chip) was placed between a Samsung S10+ and a Moshi Otto Q wireless charger, in direct contact with the charger pad. 

No phone case was used to remove any buffering effect that it may have had. The thought being that if the credit cards manage to survive this degree of exposure then they should have no problem when further protected by the barrier of a phone case. 

For reference the power output of this charging setup was 9W, and at the time of writing our credit card had been exposed to 12 hours of active charge time.

The magstripe of our credit card was in direct contact with wireless the charger pad
The power light of the Moshi Otto Q charger showed that charge was being passed into the phone battery

After wireless charging overnight, the magstripe and EMV chip were all tested on four consecutive days and found to be working just fine,demonstrating that a 9W wireless charger had no negative effect on our credit card. 

DayCard Contact Time With An Active Wireless Charger (Hours)Does The Credit Card Still Work?

Wireless charging uses radio waves and so does not emit ionizing radiation and thus presents no risk to your phone or your health.

Round up

The worry associated with wirelessly charging your smartphone while having valuable cards in the wallet plagues many. 

Though our own test demonstrated that a 9W wireless charger does not generate enough of a magnetic field, and research of others suggests that your credit cards will be just fine when placed upon a wireless charger, we recommend you take heed of Apple and Samsung’s advice and take them out of your case to stay on the safe side.


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