MagSafe Charger Only Charges at Full 15W Speeds With Apple's 20W Power Adapter [Updated]

Alongside the iPhone 12 and 12 Pro models, Apple introduced a new MagSafe charger that attaches to the magnetic ring in the back of the devices, providing up to 15W of charging power, which is double the speed of the 7.5W Qi-based wireless charging maximum.

Apple does not provide a power adapter with the $39 ‌MagSafe‌ charger, requiring users to supply their own USB-C compatible option. Apple does sell a new 20W power adapter alongside the ‌MagSafe‌ Charger, and as it turns out, that seems to be one of the the only charging options able to provide a full 15W of power to the new ‌MagSafe‌ charger at this time.

YouTuber Aaron Zollo of Zollotech tested several first and third-party power adapter options with the iPhone 12 Pro and a ‌MagSafe‌ charger using a meter to measure actual power output. Paired with the 20W power adapter that Apple offers, the ‌MagSafe‌ Charger successfully hit 15W, but no other chargers that he tested provided the same speeds.

The older 18W power adapter from Apple that was replaced by the 20W version was able to charge the ‌iPhone 12 Pro‌ using the ‌MagSafe‌ Charger at up to 13W, but the 96W Power Adapter and third-party power adapters that provide more than 20W were not able to exceed 10W when used with the ‌MagSafe‌ Charger. Below are the results from Zollo's tests:

• Apple's 20W Power Adapter - 15W
• Apple's 18W Power Adapter - 13W
• Apple's 96W MacBook Pro Power Adapter - 10W
• Anker 30W PowerPort Atom PD 1 = 7.5W to 10W
• Aukey 65W Power Adapter - 8W to 9W
• Pixel 4/5 Charger - 7.5W to 9W
• Note 20 Ultra Charger - 6W to 7W

For maximum charging speeds with the ‌MagSafe‌ Charger and an ‌iPhone 12‌ or 12 Pro, Apple's 20W power adapter is required, and older power adapter options won't work as well. Third-party companies will need to come out with new chargers that use the particular power profile that Apple is using to provide the optimum amount of power before a third-party charger will be able to provide the full 15W with the ‌MagSafe‌ Charger.

Zollo's testing also revealed that Apple is using aggressive temperature control, so when the iPhone gets warm, the charging power tends to stay below 10W. The best speeds come from charging using the 20W power adapter without a case on the ‌iPhone‌ to better let heat dissipate.

Older iPhones, such as the 11 Pro Max and 8 Plus, charged at around 5W with the ‌MagSafe‌ Charger and Apple's 20W power adapter, which is in line with the testing results we saw last week. It's not worth buying a ‌MagSafe‌ Charger to use with a non ‌iPhone 12‌.

The same goes for Android phones. The ‌MagSafe‌ Charger technically supports Qi-based charging and can work with Android devices, but when paired with an Android smartphone, the ‌MagSafe‌ charger was outputting at 1.5W, which is slow enough that it's nearly useless.

Update: With further testing, Zollo now says that some third-party chargers may work, but those chargers need to be PD 3.0 compatible with specific voltage and amperage output. MacRumors contributor Steve Moser has also shared some examples of power adapters that should theoretically charge the ‌iPhone‌ at the full 15W when used with the ‌MagSafe‌ Charger.