One of the benefits of Apple's new MagSafe Charger is that it can wirelessly recharge the iPhone 12 at 15W speeds. But now it's been revealed that the MagSafe Duo, which adds an Apple Watch charger, can't reach those peak 15W speeds.

Apple says that if you plug the MagSafe Duo charger into a Apple's 20W USB-C power adapter, your iPhone 12 will only charge at speeds up to 11W (via Bloomberg's Mark Gurman). If you use a 27W or higher USB-C power adapter with the MagSafe Duo, your iPhone 12 will charge at up to 14W speeds.

The MagSafe Duo is one accessory for charging your iPhone and Apple Watch at the same time and can fold up for easier travel. Some folks are likely to be disappointed to learn that no matter which USB-C power adapter they plug the MagSafe Duo in to, they won't get the full 15W charging speeds for the iPhone 12 that they'd get with the regular MagSafe Charger.

What's more, even getting the 14W charging speeds with the MagSafe Duo won't be cheap. The MagSafe Duo itself costs $129, but it does not include a USB-C power adapter to plug it in to. Apple's 20W USB-C power adapter is priced at $19 and that'll get you 11W charging speeds, but if you want the faster 14W speeds, you'll need to pony up $49 for Apple's 30W USB-C power adapter.

Apple's MagSafe Duo charger offers convenient charging of your iPhone 12 and Apple Watch in one accessory, and it's fold-up design will be appealing to frequent travelers. But those who do want to lighten their charging load are going to have to pay a premium to do so.

Apple hasn't said when the MagSafe Duo will launch.