Your old USB charger might not be able to fast charge the new iPhone 17s

Apple’s new iPhone models support faster charging – the iPhone 17, 17 Pro and 17 Pro Max can hit 50% in just 20 minutes, while the slim iPhone Air needs 30 minutes to get to the 50% mark. It shouldn’t surprise you – but it should disappoint you – that Apple did this in the most Apple way possible.

According to the official specs, the 20 minute time is achieved using Apple’s new 40W Dynamic Power Adapter with 60W Max. First, that’s a terrible name for a charger. Second, let’s be clear – it’s a 40W charger that can deliver 60W for a limited amount of time (over 15 minutes, according to early tests).

The important thing is that this charger uses the new Adjustable Voltage Supply (AVS) protocol instead of the older Programmable Power Supply (PPS). AVS allows the device (the iPhone, in this case) to request a certain voltage, ranging from 15V to 48V in 0.1V steps. Which is great for high-power devices, but good ol’ PPS can easily handle 40W and even 60W.

Chances are that whatever USB charger you have at home does not support AVS – but it might support PPS. That’s not the case with Apple’s new adapter, however.

The charging protocols supported by Apple’s new 40W Dynamic Power Adapter

Reddit user privaterbok did a hands-on examination of the new 40W Dynamic Power Adapter with 60W Max and confirmed that PPS is not supported – only the standard USB Power Delivery 3.0. This makes Apple’s new $39 charger less useful for any PPS-enabled gadget you may have.

The more pressing question is the opposite – can the iPhone 17 models charge to 50% in 20 minutes using a 40W (or even a 60W) USB PPS adapter? And if it does, will it do it as efficiently as an AVS-enabled charger? That’s something that we will have to test.

Apple iPhone 17

Apple iPhone 17 Pro

Apple iPhone 17 Pro Max

Apple iPhone 17 Air