Apple’s wireless charger MagSafe Duo does not work with Apple’s own 29W charger

Apple’s wireless charger MagSafe Duo does not work with the 29W charger from Apple itself, released in 2015, according to a support page. The adapter can only supply 2A at a voltage of 14.5V and there are no other options. The charger requires 5V or 9V.

Apple mentions that the MagSafe Duo, which can charge two devices wirelessly at the same time, requires a minimum of a 20W adapter. Apple’s own 29W charger from 2015 only has one output, namely 2A at 14.5V. Because the MagSafe Duo works on 5V and 9V, it does not work with the old charger.

The manufacturer replaced the 29W adapter, which came out roughly at the same time as the first MacBook with USB-C in 2015, with a 30W model in 2018. It does have multiple output options and thus complies with the USB Power Delivery standard. The newer from 2018 can supply 20V with 1.5A, but also 15V on 2A, 9V with 3A or 5V with 3A, for 15W charging.

To charge an iPhone and Apple Watch at the same time on the MagSafe Duo, a minimum of 15W is required, to be supplied via 5V / 3A or 9V / 1.67A. Then the iPhone will not charge at its fastest. The maximum charging power for an iPhone 12 via the MagSafe Duo is 14W, but this requires an adapter that can supply at least 3A over 9V for a power of 27W.