What’s the fastest way to charge an iPhone 15 Pro Max? Apple’s 30W power adapter technically wins the race. An iPhone 15 Pro Max battery charge test, however, helps make a strong case for why Apple’s 20W power adapter is the best fast charger.

Sure, Benjamin Mayo argued the point two weeks ago. “The iPhone USB-C port can technically receive power up to 27 watt speeds,” he says, “but practically speaking there are diminishing returns on charging speed above ~20-watts.” Citation needed, much? Also, he’s a small phone guy. What about us 5x zoom shooters with bigger batteries to charge?

I mostly charge my iPhone 15 Pro Max overnight with MagSafe, but I’ve been using the 30W power adapter for my MacBook Air to get the fastest charging experience over USB-C. Makes sense to me, regardless of what Mayo claims to know.

This iPhone 15 Pro Max battery charge test video, however, has convinced me that Apple’s 20W power adapter is actually the better solution. Unlike Mayo, this guy’s got receipts.

The quick and short of it is that he saved a whopping 10 minutes charging an iPhone 15 Pro Max with Apple’s 30W power adapter compared to Apple’s 20W power adapter. We’re talking 2 hours 11 minutes versus 2 hours 21 minutes. Furthermore, at no point in the video test was there a gap bigger than 4% between battery levels while charging.

If all things were equal, I’d still use my 30W power adapter over my 20W power adapter. Cumulatively, that 10 minute difference adds up to way more time to question Mayo’s logic.

Unfortunately, I can’t think of a real world scenario where I would notice the 10 minute difference, and Apple’s 20W power adapter is noticeably more compact than the 30W power adapter. This especially matters when trying to fit two power adapters side-by-side with a space-constrained power outlet.