When Apple introduced the new iPhone 17 and iPhone 17 Pro/Max, it highlighted their even faster fast-charging abilities. With an appropriate USB-C charger that can deliver at least 40 watts, it can charge up to 50 percent in just 20 minutes, where prior iPhones took 30 minutes (50 percent longer).
It also introduced an intriguing new power adapter. The 40W Dynamic Power Adapter with 60W Max is nothing if not confusing. It’s small—surprisingly so for an Apple charger with this capacity—and seemingly made for iPhones. But what does “60W max” even mean? If it can go up to 60 watts, shouldn’t it just be called a 60-watt power adapter? And what is it even for, if none of the new phones need it to charge as quickly as possible?
Let’s break down this new power adapter and what it can do.
Dynamic Power Explained
Apple’s new USB-C power adapter can sustain continuous power of up to 40 watts using the USB-PD (USB Power Delivery) standard. That’s up to 20 volts at 2 amps or 15 volts at 2.67 amps, if you want to get technical.
But the adapter supports a new USB-C charging standard called AVS (Adjustable Voltage supply) that allows it to boost the power up to 3 amps without renegotiating the voltage delivery, going up to a possible 3 amps at 20 volts, or 60 watts.
So if it can do 60 watts, why isn’t it just a 60-watt power adapter? Well, the power adapter can only hold that rate until either it or the device it is charging can’t maintain it. Usually, that happens because it gets too hot. According to some independent tests, it seems to take about 15-20 minutes at 60 watts for Apple’s power adapter to get too hot and back off. That’s why it says “60W max” rather than being listed as just a 60W power adapter: it won’t sustain 60 watts all the time.
There’s another USB-PD standard called PPS (Programmable Power Supply) that is very similar to AVS, but actually a totally different protocol and completely incompatible. A number of existing third-party USB-C chargers support this standard, but Apple doesn’t. Each has its own tradeoffs from a geeky engineering perspective, but as far as consumers are concerned, they’re not all that different. The AVS standard seems to allow more rapid and fine-grain adjustments, so it can stay closer to the ideal power level as charging conditions change.
Will it charge your iPhone more quickly?
Short answer: Nope!
While Apple’s new iPhones might support the new USB-PD AVS standard, they never really seem to draw more than around 25-28 watts, no matter what adapter you pair them with. Apple recommends at least a 40W power adapter to maximize charging speed (as no power adapter is perfectly efficient), but the boost up to 60 just isn’t necessary or helpful here.
I tried the new “40W with 60 Max” power adapter on the iPhone 17 and compared it with a couple of other, older power adapters. In every case, the iPhone 17 charged at about the same rate.
Apple 61W USB-C Power Adapter: 20 minutes charged from 0 to 42 percent, the max power draw was ~26W.
Apple 40W/60W Dynamic Power Adapter: 20 minutes charged from 0 to 41 percent, the max power draw was ~26W.
Foundry
However, this new Dynamic Power Adapter will deliver more juice to your MacBook or other higher-power modern Apple Device. We had no problem charging a M2 MacBook Air at a rate of 57 watts.
Foundry
While Apple’s new dynamic power adapter’s core benefit (the ability to boost to 60 watts for a while and continuously fine-tune charging rate with compatible devices) doesn’t really do a whole lot for iPhone users. iPhones just don’t draw enough power for it to matter.
The higher max power rate is of benefit to those with modern Apple products that can draw more power, though, and we suspect this adapter is a bit of future-proofing for iPhones and iPads that may have a higher peak charge rate when using a power adapter that supports the USB-PD AVS standard.
