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Tested

Every charger from the Watt Check series, measured on a MacBook Air: advertised Power Delivery profiles, the negotiated contract, and the live draw. Rated vs. real, one page per charger.

Every charger tested in the Watt Check video series gets a page here: the full Power Delivery profile menu it advertises, the contract the Mac actually negotiated, and the live power draw - all read from macOS itself by USB Connection Information.

The rig and reasoning are documented in the testing methodology, and the hardware in the gear list. New chargers are added as episodes are published.

  • Apple 96W USB-C Power Adapter on a MacBook Air: Measured

    Negotiates 94 W at 4.7 A - the largest contract in the series. Swap to a non-e-marked cable and the same adapter drops to 60 W, with the app naming exactly what's missing.

    See the measurements →
  • Apple 40W Dynamic Power Adapter (60W Max) on a MacBook Air: Measured

    One charger with two ratings. It offers 40 W sustained and a 60 W peak marked DPS, and the Mac negotiates the peak - drawing 56.1 W live.

    See the measurements →
  • Dell WD22TB4 Thunderbolt Dock on a MacBook Air: Measured

    Negotiates 90 W at 4.5 A while simultaneously carrying Thunderbolt 4 at 40 Gbps and a Realtek gigabit LAN adapter. One cable doing what a charger cannot.

    See the measurements →
  • Anker 20,000mAh Power Bank on a MacBook Air: Measured

    Delivers 62.3 W to a laptop from a battery, with five fixed profiles and PPS up to 5 A. It also identifies itself as Chipsea Technologies - the PD controller chipmaker, not Anker.

    See the measurements →
  • UGREEN 30W Charger on a MacBook Air: Measured

    Delivers its full 30 W and offers that rating three times over - at 12 V, 15 V and 20 V. The most flexible fixed-profile menu in the series.

    See the measurements →
  • AUKEY 20W Charger on a MacBook Air: Measured

    Delivers its full 20 W, but over a 12 V rail rather than the usual 9 V - and offers that rating on both. Includes PPS up to 2 A.

    See the measurements →
  • Apple 35W Dual USB-C Power Adapter on a MacBook Air: Measured

    One port in use: the full 35 W. Second port occupied: every profile drops to about 17 W. The same adapter, measured both ways.

    See the measurements →
  • Apple 30W USB-C Power Adapter on a MacBook Air: Measured

    The M1 MacBook Air's bundled charger delivers 28.4 W and offers its full 30 W twice, on two different rails. It also reports its own manufacturer and product name.

    See the measurements →
  • Anker Nano 30W GaN on a MacBook Air: Measured

    Delivers 28 W live, offers its full 30 W on two different rails, and adds a PPS range for phones. It also reports no name at all - macOS just calls it 'Power Supply'.

    See the measurements →
  • Anker 20W Nano Pro on a MacBook Air: Measured

    Delivers its full 20 W at 9 V. The readout is byte-for-byte identical to Apple's 20W cube: same two profiles, same active rung, same live draw.

    See the measurements →
  • Apple 20W USB-C Power Adapter on a MacBook Air: Measured

    The iPhone cube delivers its full 20 W to a MacBook Air, from just two profiles with no 15 V or 20 V laptop rail. 9 V x 2.22 A is 20 W exactly - a designed number.

    See the measurements →
  • Apple 18W USB-C Power Adapter on a MacBook Air: Measured

    Delivers its full 18 W from just two profiles. Famous for being 0.22 A short of what the HomePod mini demanded at launch - until a software update relaxed the requirement.

    See the measurements →
  • Dell 65W USB-C Charger on a MacBook Air: Measured

    Delivers its full 65 W, using a 3.25 A top rung that a 3 A cable can't carry. It reports itself only as 'pd charger' - the Dell name comes from its PD vendor ID.

    See the measurements →
  • Amazon Basics 68W GaN Charger (PD68U) on a MacBook Air: Measured

    The USB-C port delivers its full 60 W, and drops live to 50 W the moment the USB-A port is loaded. 68 W is a shared budget, not the sum of the two ports.

    See the measurements →
  • Apple 5W USB-A Charger (A1385) on a MacBook Air: Measured

    The classic iPhone cube delivers 4.6 W to a MacBook Air. No fast-charge profile at all - just a plain 5 V / 1 A port, capped by the charger itself.

    See the measurements →
  • Apple 12W USB-A Charger (A1401) on a MacBook Air: Measured

    Rated 12 W, delivers 7.1 W to a MacBook Air - identical to the 10W brick. The twist: a USB-C iPhone still pulls the full 12 W from this same charger.

    See the measurements →
  • Apple 10W USB-A Charger (A1357) on a MacBook Air: Measured

    Rated 10 W, delivers 7.1 W to a MacBook Air. The Mac won't use Apple's legacy 2.1 A signaling, so both sides fall back to BC 1.2 and its 7.5 W ceiling.

    See the measurements →

© 2025–2026 Daniel Gauthier

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