A Golf Ball That Charges a MacBook: Measured

A novelty golf-ball-shaped 20W charger with one USB-C and one USB-A port, measured on a MacBook Air M5: 18.9 W delivered - and a Power Delivery profile menu identical to an unrelated charger from another brand.

A novelty golf-ball-shaped 20 W charger with one USB-C port and one USB-A port, tested on its USB-C port against a MacBook Air M5 with a low battery, per the methodology . It is shaped like a golf ball. It is otherwise an ordinary GaN charger, and it performs like one.

The numbers

Rated20 W
Negotiated20 W (12 V up to 1.67 A)
Live draw18.9 W (11.9 V at 1.59 A)
ProtocolUSB PD 3.0

Profile menu:

ProfileRail
15 W5 V up to 3 A
20 W9 V up to 2.22 A
20 W12 V up to 1.67 A — active
PPS3.3-5.9 V, up to 3 A

You have seen this menu before

That profile list is the same one advertised by the Target dealworthy 20W car charger — a Target house brand, sold in a different shape, for a different socket, in a different aisle.

Same four entries, same wattages, same active rail at 12 V and 1.67 A, and the same PPS window of 3.3 V to 5.9 V. That last one is what makes it more than coincidence: PPS ranges in this series usually reach 11 V or higher, and a window that stops at 5.9 V cannot even reach its own charger’s 9 V step. Two unrelated products independently choosing that same unusual limit is not plausible.

What is far more likely is that both are built on the same reference design — the same USB-PD controller, running the same default profile table the chip vendor ships. The outside is moulded by whoever is selling it. The negotiation is not.

This is ordinary in the no-name charger market, and it is worth knowing when you shop: the shape, the brand on the box and the price are the parts that vary. The PD profile ladder is a fingerprint of who actually built the thing. A charger that reports an unusual profile menu identical to another charger’s is the same charger wearing a different shell.

It holds its rail, and that is the difference

Here is where the two part company. Both negotiate the same 12 V contract. Under load:

NegotiatedDelivered
Golf ball12 V11.9 V
Dealworthy car charger12 V11.0 V

USB PD allows a fixed supply within ±5%, so a 12 V rail should stay above about 11.4 V. This one sits comfortably inside at 11.9 V. The car charger does not.

Same silicon, different result — and the reason is the input, not the design. This charger runs from mains and steps a rectified high voltage down to 12 V, which is the easy direction. The car charger is fed from a car’s 12 V accessory socket that sags under load, and producing a clean regulated 12 V out of an unregulated nominal 12 V in is a genuinely harder job. The shared reference design is doing the same work in both; only one of them has a comfortable input.

Worth buying?

As a charger, it is fine — 18.9 W of a 20 W rating, well-behaved voltage, one USB-C and one USB-A port. It will fast-charge a phone and trickle a MacBook Air. As a 20 W charger it is neither better nor worse than the many identical-inside units next to it on the listing page.

Buy it because it is a golf ball. That is the actual feature.

The unit

The golf ball charger tested here, 20 W with one USB-C and one USB-A port.

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