iPhone 18 Pro Is the First iPhone That Actually Needs AVS Charging
The iPhone 18 Pro needs an Adjustable Voltage Supply (AVS) charger for 50% in 15 minutes. What AVS is, which chargers qualify, and what Apple hasn't said yet.
When Apple released the 40W Dynamic Power Adapter with 60W Max alongside the iPhone 17 in 2025, it was one of the first chargers to advertise Adjustable Voltage Supply (AVS), a newer USB Power Delivery feature. Then no iPhone seemed to use it. Macworld measured an iPhone drawing about the same form Dynamic adapter as from Apple’s 61W adapter, which has no AVS at all.
The iPhone 18 Pro changes that. Its fastest wired charging spec names AVS explicitly, which makes it the first iPhone, the first Apple device, and possibly the first mainstream device of any brand to actually use AVS. Even Google’s new Pixel 11 Pro XL still fast charges over 21 V PPS, not AVS.
What Apple’s spec sheets say
| Model | Fastest wired charge | What Apple asks for |
|---|---|---|
| iPhone 18 Pro / 18 Pro Max | 50% in around 15 min | 60W-capable USB PD 3.1 (or better) adapter with AVS, plus a 60W-capable USB-C cable |
| iPhone Duo | 50% in around 20 min | 60W-capable USB PD adapter, plus a 60W-capable USB-C cable - no AVS |
| iPhone 17 / 17 Pro / 17 Pro Max | 50% in around 20 min | 40W adapter or higher |
From Apple’s iPhone 18 Pro specs, iPhone Duo specs, and fast-charging support article.
Two details stand out.
The AVS requirement is wired-only. MagSafe on both the iPhone 18 Pro and the iPhone Duo is listed as 50% in around 30 minutes with a 35W adapter and a MagSafe Charger, at up to 25 W. AVS isn’t mentioned.
The iPhone Duo skips it. Apple tested the Duo on the same 40W Dynamic Power Adapter, but its footnote only asks for USB PD power adapters. So AVS isn’t a blanket rule for Apple’s 2026 phones, it’s specific to the Pro models and their 15-minute claim.
What AVS actually does
A standard USB-C charger offers a short menu of fixed voltages - 5, 9, 15 and 20 V - and the device picks one. The phone then converts that voltage down to whatever its battery needs at that moment, and the conversion loss ends up as heat inside the phone.
AVS lets the device request a precise voltage anywhere inside a range instead. Apple’s Dynamic adapter lists two ranges on its label: 9-15 V at 2.67 A and 15-20 V at 2 A, each able to peak at 3 A - 60 W at the top of the range (my measurement). Start closer to the voltage the battery wants, and there’s less to convert, less heat, and fast charging that can be held for longer. Heat, is usually what forces a phone to slow down to prevent batttery degradation.
If you know PPS (Programmable Power Supply) from Android fast chargers, AVS is the same idea in a newer, simpler form. They’re separate entries in a charger’s profile list, though: a charger with PPS doesn’t automatically support AVS, and Apple’s spec sheets have never asked for PPS.
The 40W Dynamic Power Adapter finally has a job
For a year, the AVS in Apple’s own charger was a feature waiting for an iPhone:
- iPhone 17: about 26 W peak from the Dynamic adapter, identical to the 61W adapter (Macworld).
- iPhone 17 Pro Max: around 36 W peak across Apple’s chargers, from the 40W Dynamic all the way up to the 140W (MacRumors).
No iPhone 17 model pulled more power because the charger had AVS. With the iPhone 18 Pro, Apple puts a number on what AVS is for: 50% in around 15 minutes, five minutes faster than the iPhone 17 Pro.
First measurement: 54 W at 17.33 V
MKBHD has measured an iPhone 18 Pro charging over USB-C: a maximum of 54 W, with a reading of 17.33 V at 2.984 A.
The voltage is the giveaway. Standard USB-C chargers only offer fixed steps of 5, 9, 15 and 20 V, and 17.33 V isn’t one of them. It sits inside the 15-20 V AVS range, which is exactly what AVS is for: the phone asking for a precise voltage instead of settling for the nearest fixed step. The current, just under 3 A, is right at the limit of a 60W-capable USB-C cable.
That’s well past the roughly 36 W peak measured on the iPhone 17 Pro Max, and a clear sign the iPhone 18 Pro is actually using AVS rather than just listing it.
Open question 1: Will third-party AVS chargers get the full speed?
On paper, yes. Apple’s footnote doesn’t say “Apple adapter” - it says USB PD 3.1 (or better) power adapters with AVS, plus a 60W-capable cable. Right now, the one charger known to meet that description is Apple’s own. Third-party chargers advertising AVS are appearing from brands like UGREEN and Baseus, but nobody has published measurements of an iPhone 18 Pro hitting 15 minutes on one yet.
If you’re shopping for one, two things on the spec sheet matter:
- The AVS range has to reach 60 W. Look for an AVS range that goes up to 20 V at 3 A. A charger can support AVS and still top out lower - “has AVS” and “60W-capable with AVS” aren’t the same claim.
- “PD 3.1” alone isn’t proof. AVS first appeared in PD 3.1 only as part of Extended Power Range (EPR), the laptop tier that goes up to 48 V and needs an EPR cable. The AVS ranges a phone uses, between 9 and 20 V, were added in PD 3.2. A charger listing PD 3.2 together with an AVS range covering 9-20 V is the combination to look for.
Box copy is where this goes wrong, so it’s worth checking the charger itself. Plug it into your Mac or PC with USB Connection Information and it lists every Power Delivery profile the charger advertises, including any adjustable PPS or AVS range, along with the contract your computer negotiated and the live wattage.
Open question 2: Will it pull more than 40 W without AVS?
Apple only gives the AVS figure for the iPhone 18 Pro. It doesn’t say what happens on an ordinary 60 W or 100 W USB-C charger that sticks to fixed voltages, the kind most people already own.
The reasonable expectation is iPhone 17 Pro-class charging, around 20 minutes to 50%. Whether the 18 Pro goes beyond the roughly 40 W the iPhone 17 generation tops out at when it’s on fixed profiles is something only measurements will settle.
The iPhone Duo is a hint worth noticing. It asks for a 60W-capable charger and doesn’t require AVS, so the 18 Pro’s AVS requirement looks like a deliberate choice for the Pro models rather than a hard limit of Apple’s 2026 hardware.
Open question 3: Will older iPhones get AVS?
Apple hasn’t said. Its support article still lists a 40W adapter for the iPhone 17 family’s fastest charge with no mention of AVS, and the measurements above show no AVS benefit on the iPhone 17 today.
A software update could only change that if the iPhone 17’s charging hardware can already speak AVS, and Apple hasn’t said whether it can. Until an iOS update changes the spec sheet or the measurements, treat AVS fast charging as an iPhone 18 Pro feature.
What to use right now
- iPhone 18 Pro or Pro Max, fastest wired charging: the Apple 40W Dynamic Power Adapter with 60W Max is the safe choice until third-party AVS chargers are measured. Its full profile list is in my test.
- Cable: any compliant USB-C to USB-C cable is rated for at least 3 A, which is 60 W at 20 V. A phone doesn’t need a 100W or 240W e-marked cable.
- iPhone Duo: any 60W-capable USB PD charger. AVS isn’t required.
- iPhone 17 family: any USB PD charger of 40 W or more. AVS won’t make it faster.
- MagSafe on iPhone 18 Pro or iPhone Duo: a 35 W or higher USB-C adapter with Apple’s MagSafe Charger. AVS doesn’t matter here. If it’s Apple’s 35W Dual adapter, leave the second port empty. With both ports in use, each drops to about 17 W.
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