Safety needs vigilance. All products that transfer electrical power inherently have the potential to do harm, and manufacturers must take care to use suitable components and implement safety precautions.
Cheap traditional mobile phone chargers that connect with the phone via a USB or Lightning connector are sometimes made with poor quality components that fail to meet safety regulations to cut costs. This means they can cause injury, electric shocks and even fires.
“It is highly advised that consumers should check the credibility and the ratings of the online sellers before purchasing products in order to avoid fake products that can potentially risk their life.”
“Because fake chargers can be erratic in nature when it comes to supplying electricity, they might just end up nuking your whole phone. Your phone’s processor might end up fried. Some people have seen their phones explode as well.”
“Don't buy a counterfeit charger; the price is great, but it's not worth risking your expensive device or your safety.”
Wireless mobile phone chargers need the same careful attention to safety as traditional wired chargers.
Safety features for wireless chargers
The Qi standard for wireless charging mandates the implementation of safety features. These features prevent safety hazards such as:
Risk of injury
Objects placed in the vicinity of wireless chargers, or between the charger and the phone, must not get hot to prevent injury such as 3rd degree skin burns. The Qi specification mandates foreign object detection measures that help prevent this from happening.
Risk of device damage
Overheating degrades the battery and shortens battery life. Temperatures above 100°C / 212°F can melt phone cases and potentially damage surfaces in contact with a uncertified charger or a uncertified smartphone cover or case. The Qi specification mandates thermal testing of wireless chargers and mandates effective magnetic shielding of the battery to minimize heating of the battery and mobile phone.
A badly designed wireless charger may induce a high voltage inside mobile phones and other electronic products placed in the vicinity of the wireless charger. High voltages can damage electronic products. The Qi specification mandates magnetic field strength limiting measures that limit the voltages that are induced in other products.
Risk of incompatibility
Uncertified products may be incompatible with other wireless charging products.
Certification program for wireless charging products
The Wireless Power Consortium operates a certification program for wireless charging products. Certified products have passed a series of compliance tests and interoperability tests. These tests verify that the product has implemented all mandatory safety features, as well as features that are necessary to ensure interoperability of wireless power transmitters and power receivers.
Method 1: By the Qi logo.
The Qi logo may be used only on Qi Certified products. The logo and the word 'Qi' are registered trademarks of the Wireless Power Consortium in most countries. Use of these trademarks requires a trademark license. A product that has the Qi logo implicitly claims that it is Qi Certified.
This is a simple method, but not always secure because it is may be circumvented by manufacturers of fake products, simply by printing a counterfeit Qi logo on the product. It is, however, a useful indicator for consumers who may not have the patience to use the more secure methods 2 and 3.
A product is licensed to use the Qi logo (and the name 'Qi') in product documentation and advertisements only when it is registered in the Qi Certified Product Database. The product is authorized to use the trademarks when the database contains an exact match for Brand Name, Product Name, and Type Number.
The Wireless Power Consortium issues a certificate for products that are Qi Certified. Such certificate is genuine only when the URL encoded in the certificate brings you to a page on our website that shows the same product.
Method 2 is the recommended method for professional buyers of wireless charging products. We recommend that buyers demand that their supplier provides a Qi Certificate of Registration as proof that the product has passed all mandatory tests.
Method 3: By verifying that the product is in the on-line Qi Certified Product Database
The Qi Certified Product Database contains a list of Qi Certified products. If you are uncertain whether a product is Qi Certified, you can check the database for an exact match of Brand Name, Product Name, and Type Number.
Method 3 is the recommended method to make sure that a product you see advertised is Qi Certified and has passed all mandatory tests.
Safety considerations per product category
Wireless phone chargers in automobiles
Automotive wireless chargers installed as original equipment by the vehicle’s manufacturer are usually Qi Certified even if the vehicle is not listed in the Qi Certified Product Database.
We recommend to verify the Qi certification status of all aftermarket automotive wireless chargers (not pre-installed or sold under a brand name that is not the same as the vehicle’s brand). You can verify the certification of aftermarket wireless chargers using Methods 2 or 3.
Mobile phones with integrated support for wireless charging
Mobile phones with integrated support for wireless charging are usually Qi Certified, even if they do not bear the Qi logo. You can verify certification of a wireless charging phone using Methods 2 or 3.
Smartphone covers that support wireless charging
The members of the Wireless Power Consortium offer a wide range of Qi Certified smartphone covers for use with mobile phones that don’t have integrated support for wireless charging.
Making a safe smartphone cover is difficult and expensive. The cover must provide adequate magnetic shielding (to make sure the battery will not get hot) and the smartphone cover must measure the received power accurately (to make it possible for the wireless charger to detect undesirable energy losses caused by heating of objects in the vicinity of the wireless charger).
Fake smartphone covers, that are not Qi Certified, may provide insufficient shielding, they may get hot themselves, and they may cause heating of objects in the vicinity of the wireless charger.
Smartphone covers are certified for a specific phone model. For example, a Qi Certified cover for an iPhone 6 should not be used with an iPhone 7. The information in the Qi Certified Product Database will tell you for which phone model the cover is certified.
The members of the Wireless Power Consortium offer a wide range of Qi Certified wireless chargers.
Wireless chargers must implement foreign object detection, limit the voltage induced in mobile phones, and use high quality components that transfer power efficiently, without getting hot.
Fake wireless chargers that are not Qi Certified may not have implemented all mandatory safety features to save cost. They may get hot and damage phones or other products placed on the charger.
Examples of fake wireless charging products
A receiver that disables the detection of metal objects
Here is an example of an uncertified wireless power receiver we purchased at a major on-line retailer. The product is made anonymous because it is an example.
We had this wireless charging receiver tested by an independent test lab. This test lab measured the product and found that it fails an important safety test.
This “Test Req#57” verifies that the receiver reports the received power correctly. In this case, the product exaggerates the amount of power that is received. The consequence of this failure is that wireless charger will not be able to detect metal objects in the vicinity of the charger, and the mobile phone can get hot or these metal objects can get hot.
Click to enlarge
A transmitter that makes metal objects hot
We purchased an uncertified wireless charger.
This product fails test 18.104.22.168 “Object heating prevention”. In this test a series of metal objects are placed between the charger and a receiver. As you can see in the test report, the temperatures of most test objects exceed the maximum value allowed for that test object. One test object reaches 96.1 Celsius (205 Fahrenheit) in 51 seconds.
Click to enlarge
This is an example of an uncertified wireless charger that does not properly implement the detection of metal objects in the vicinity of the charger.
Beware of misleading claims - “Qi Certified” is not the same as “Qi compatible”
Some manufacturers use misleading claims to hide the fact that their products have not been tested.
These are examples of claims that can be misleading:
- “Qi compatible”
- “Qi compliant”
- "Works with Qi"
- “Works with Galaxy S7 and all Qi-enabled devices”
- “Compatible with the Qi standard”
- “Compatible with all Qi-enabled devices”
It is not possible to determine compatibility and safety without extensive testing. Demand that products are Qi Certified. Demand proof that the product has passed all mandatory compliance tests and interoperability tests. Learn about “Recognizing a genuine Qi Certified product” in the section above, or in the Qi Certified section of the WPC website.
The Wireless Power Consortium shall not be held responsible for any damage, direct or indirect, that may be caused by the user of any Qi certified product or any uncertified product that claims compliance with the Qi specification. Product manufacturers are responsible for ensuring that their products meet any applicable product safety regulations. Certification by the Wireless Power Consortium does not guarantee product safety. Please consult one of the Qi Authorized Test Labs to learn more about product safety certification of wireless power products. Qi Certification of a product is not an endorsement of the product. Qi and the Qi logo are registered trademarks of the Wireless Power Consortium in most countries and all other trademarks included above are the property of their respective owners.