0 → 50%
Full-speed constant current. Your charger matters here. Only here.
50 → 80%
Current tapers. Better charger still helps. Less than you'd think.
80 → 100%
Trickle charge. 140W and 20W finish the same. Chemistry doesn't negotiate.
Stock
The charger in the box (iPads, Macs), or a 20W USB-C (iPhones — no charger included since 2020).
Optimal
The fastest charger the device can actually use. More watts than this won't help -- the device caps out.
| Device | Max W | MagSafe / Qi2 |
0→50% 20W |
0→50% Optimal |
Faster |
|---|---|---|---|---|---|
| iPhone 18 Pro Max (~21.4 Wh) | 60W† | 25W | ~41m† | ~15m† | 63% |
| iPhone 18 Pro (~16.5 Wh) | 60W† | 25W | ~32m† | ~15m† | 53% |
| iPhone Duo (two cells, Wh unpublished) | 60W† | 25W | ~40m† | ~20m† | 50% |
| iPhone 17 Pro Max (19.6 Wh) | 40W | 25W | ~38m | ~20m | 47% |
| iPhone 17 Pro (16.0 Wh) | 40W | 25W | ~31m | ~20m | 35% |
| iPhone 17 (14.0 Wh) | ~27W | 25W | ~28m | ~20m | 29% |
| iPhone 17e (15.4 Wh) | 20W | 15W | ~30m | ~30m | — |
| iPhone 16 Pro Max (18.0 Wh) | 30W | 25W | ~30m | ~26m | 13% |
| iPhone 16 Plus (18.0 Wh) | ~27W | 25W | ~30m | ~27m | 10% |
| iPhone 16 (13.7 Wh) | ~23W | 25W | ~30m | ~27m | 10% |
| iPhone 15 Pro Max (17.3 Wh) | 27W | 15W | ~30m | ~27m | 10% |
| iPhone Air (12.3 Wh) | ~20W | 20W | ~30m | ~30m | — |
The Air and 17e both cap at 20W — a 140W charger finishes at the same speed as a basic 20W. Save the good charger for a device that can use it. The MagSafe / Qi2 column is the wireless ceiling: 25W on the 16 line and up (minus the 17e), and a Qi2 pad from anyone hits the same number as Apple's puck, provided the adapter behind it is 30W or better (35W on the 17 and 18 lines). Wireless is still the slow lane; 25W gets an 18 Pro to 50% in about 30 minutes, twice the wired time.
† Apple's numbers, not the lab's. The 18 Pro ships September 18 and the Duo October 23, so ChargerLAB hasn't had either on the bench; those times are estimates and get corrected when the tests land. The catch in the 15-minute claim: it needs a 60W adapter that supports AVS (Adjustable Voltage Supply, the trick that lets a 40W brick surge to 60W). Right now the only one on the shelf that qualifies is Apple's own $40 40W Dynamic Power Adapter. The Anker below has an AVS mode on paper but nobody has tested it with an 18 Pro yet; without AVS, an 18 Pro charges like a 17 Pro, about 20 minutes to 50%. Still not bad.
| Device | Ships With |
Max W | 0→50% Stock |
0→50% Optimal |
Faster |
|---|---|---|---|---|---|
| iPad Pro 13" M5 (39.0 Wh) | 20W | 60W | ~1h 30m | ~30m | 67% |
| iPad Pro 11" M5 (31.3 Wh) | 20W | 60W | ~1h 15m | ~25m | 67% |
| iPad Air 13" M4 (36.6 Wh) | 20W | ~31W | ~1h 25m | ~55m | 35% |
| iPad Air 11" M4 (28.9 Wh) | 20W | ~31W | ~1h 10m | ~45m | 36% |
| iPad mini 7 (19.3 Wh) | 20W | ~20W | ~45m | ~45m | — |
The Pro starts at $1,199 and charges at 60W. Apple included a 20W charger, one-third speed. I have feelings about this. (The M5 Pro is the first iPad Apple calls fast-charging; the M4 topped out around 35W.)
| Device | Ships With |
Max W | 0→50% Stock |
0→50% Optimal |
Faster |
|---|---|---|---|---|---|
| MBP 16" (Pro/Max) (100 Wh) | 140W | 140W | ~26m | ~26m | — |
| MBP 14" (all configs) (72.4 Wh) | 70–96W | 96W | ~30–35m | ~30m | 0–14% |
| Air 15" M5 (66.5 Wh) | 40W | ~70W | ~52m | ~30m | 42% |
| Air 13" M5 (53.8 Wh) | 40W | ~70W | ~45m | ~26m | 42% |
| MacBook Neo (36.5 Wh) | 20W | 30W | ~1h 25m | ~55m | 35% |
Airs fast-charge at 70W but now ship with 40W — better than the old 30–35W, but still almost half-speed. The Neo ships with 20W on a 30W device — the biggest gap in the laptop lineup. The base M5 and 16-core Pro ship with 70W — below their 96W fast-charge threshold. As of macOS Tahoe 26.4, Apple will literally tell you — an orange "Slow Charger" label appears in the battery menu when your adapter can't keep up. One regional note: since April 2026, EU and UK MacBooks ship with no charger at all. The Common Charger Directive required Apple to offer a charger-free option, and Apple made it the only one. The Ships With column is the US answer.
Apple Watch Series 12, Ultra 4 · Fast-charges to 80% in 30–45 min (Series 12 ~30, Ultra 4 ~45) — but only with the Apple USB-C Magnetic Fast Charging Cable and any USB-PD adapter (5W+). Wrong cable? Roughly twice as slow.
AirPods Pro 3, 5, Max 2 (USB-C) · 3–5W. Any charger. These actually don't care. (The $129 AirPods 5 case is USB-C only; the $149 one adds Qi and the Watch puck.)
The Apple Charging Situation
Heat
The #1 killer. At 45°C (113°F), lifespan is halved vs. 20°C (68°F). A phone on a hot dashboard with a 5W charger degrades faster than fast-charging indoors at room temperature.
Time at 100%
High voltage stresses the cell. Optimized Battery Charging exists specifically to minimize this — holding at 80% overnight instead of sitting at 100% for hours.
Charge Depth
Shallow cycles (30–80%) are gentler than deep ones (0–100%). Apple already accounts for this in their specs. Don't obsess.
Charge Speed
Least important for Apple devices. The charge curve tapers so aggressively that "fast charging" only hits peak wattage for ~15 minutes, then throttles back on its own.
Ranked by actual impact. Most people worry about #4. They should worry about #1.
| If charging stops at | Battery lasts for | vs. 100% |
|---|---|---|
| 100% | 300–500 cycles | baseline |
| ~90% | 600–1,000 cycles | ~2× |
| ~80% | 1,200–2,000 cycles | ~4× |
| ~70% | 2,400–4,000 cycles | ~8× |
"This is the math behind Optimized Battery Charging. Every 10% Apple holds back roughly doubles battery lifespan."
Optimized Battery Charging
Learns your routine. If you unplug at 7 AM, it holds at 80% overnight and tops off at ~6:30 AM. Cuts time at max voltage from 8 hours to ~90 minutes.
Charge Limit (iOS 17+ / macOS Sequoia+)
Manual cap between 80–100% in 5% steps. Built for the "MacBook lives on the desk" crowd. If you keep devices 3+ years, this one's for you.
Thermal Throttling
Monitors temperature in real time. Reduces power when hot, pauses entirely if too hot. That steep wattage drop in the charge curve? That's this kicking in.
Cold Charging Block
Below 0°C (32°F), charging is blocked entirely — cold causes permanent damage. Between 0–10°C (32–50°F), charge speed is reduced automatically.
Slow Charger Warning (macOS Tahoe 26.4+)
Orange "Slow Charger" label in the battery menu and Battery settings when your adapter isn't delivering full power. Apple's own admission that the charger in the box might not be enough.
Above 80%, the battery is working its hardest — voltage spikes, chemistry gets stressed, wear accelerates. Apple knows. That's why all five of these exist. Also: USB-C means the device controls wattage, not the charger. A 140W brick on an iPhone delivers only what the iPhone asks for. You can't overfeed it — the device won't draw more than it's designed for. (The USB-PD spec goes to 240W and Framework now ships one; no Apple device asks for more than 140W.)
| Device | Cycles to 80% |
|---|---|
| iPhone 15 and later | 1,000 |
| iPhone 14 and earlier | 500 |
| All modern MacBooks | 1,000 |
A "cycle" isn't plug-in to unplug. It's 100% of capacity used cumulatively. 50% today + 50% tomorrow = one cycle.
Two phones with identical cycle counts can have very different health. The difference? Heat exposure, charge habits, and how often they sat at 100%. Cycles are the odometer. Temperature is the road.
Optimized Battery Charging is on by default. Your phone holds at 80% most of the night and tops off before your alarm. The "8 hours at max voltage" thing people worry about? Doesn't happen anymore.
Batteries don't trickle-charge. At 100%, charging stops. Dips a few percent, tops back up. The concern was never overcharging — it was sustained high voltage. Apple fixed it years ago. Plug in. Go to sleep.
USB-C1 (up to 140W solo)
MacBook — priority port, gets the most watts
USB-C2 (up to 140W solo)
iPad, second laptop, or iPhone 18 Pro
USB-C3 (up to 140W solo)
iPhone, Watch puck, AirPods — whatever's left
| Ports Active | Split |
|---|---|
| One port | 140W |
| Two ports | 100W + 60W |
| All three | 100W + 30W + 30W |
160W total. Splits shown are for Standard (C1 Priority) mode. AI mode redistributes dynamically. The display shows you exactly who's getting what.
Apple shipped this 5W charger with every iPhone from 2007 to 2019. Then stopped including chargers entirely. Hundreds of millions still in drawers. And yes — it's USB-A, so you need a USB-A to USB-C cable for anything made after 2023. Still in use. Still slow.