Chargers advertised as “iPhone 17 exclusive 40W AVS fast chargers” have appeared on the market, but such a message seems more like a marketing gimmick than a real benefit for users. The AVS label itself may sound like a new technology that brings faster and better charging to the iPhone, but the situation is much simpler.
AVS, or Adjustable Voltage Supply, is not an Apple exclusive protocol, but part of the USB-PD 3.1 standard defined by the USB-IF organization. Its main role is more accurate voltage adjustment during charging, in order to reduce energy losses and heating of the device.
AVS charging for iPhone 17 without real use
With classic USB-PD charging, there are fixed voltage steps, for example 10 V, 15 V or 20 V. If the device needs a voltage between these values, the system must additionally convert the voltage, which brings certain losses and more heat. AVS solves that problem by enabling finer voltage adjustment in 100 mV increments, so the charger can more accurately deliver what the device needs.
Apple was one of the first to commercially apply this technology back in 2021, with the 16-inch MacBook Pro model with USB-PD 3.1 charging up to 140 W. This makes much more sense for laptops, because AVS in the PD 3.1 standard targets the EPR range from 15 V to 48 V, i.e. high-power scenarios.
Later, through USB-PD 3.2, the SPR AVS range from 9 V to 20 V was introduced, which is closer to telephones. Apple then introduced a new 40 W dynamic adapter, but it is placed among Mac accessories, not among iPhone accessories. This is an important detail that marketing often skips.
The problem is that the iPhone 17 series does not currently support AVS. This means that the charger may have AVS support, but the phone will not benefit from it at all. In practice, the iPhone 17 will continue to be charged through the usual USB-PD mode, so an ordinary high-quality PD charger remains quite sufficient.
That’s why the “iPhone 17 exclusive AVS charger” should not be seen as a necessary purchase. AVS is a useful and technically good technology, especially for devices with higher power, but until the iPhone actually supports it, such a label on the charger benefits accessory manufacturers more than users themselves.