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| Apple MacBook Pro 16 M5 Max |
The power struggle continues as Apple's most expensive laptop faces charging limitations under heavy workloads
A few months ago, we highlighted a concerning issue affecting the smaller MacBook Pro 14—its 96-watt power adapter simply couldn't keep up during demanding tasks. Even more frustrating? Upgrading to Apple's own 140W adapter offered no solution due to a device-imposed power intake cap. Now, we're seeing the exact same problem plague Apple's most powerful mobile machine yet: the MacBook Pro 16 with the M5 Max chip.
The Real-World Performance Problem
After extensive testing, we've discovered that the 140-watt adapter included with the MacBook Pro 16—or sold separately in the EU—fails to meet energy demands during sustained heavy workloads. And this is despite the M5 Max already being significantly throttled by thermal constraints. In fact, the device is being held back on two fronts: limited power delivery and insufficient cooling.
During our rigorous stress test combining both CPU and GPU loads, the M5 Max briefly spikes to an impressive 114 watts (CPU and GPU only; memory power consumption is not included here) before settling at around 70 watts—at least when operating in High Power mode. But here's where things get interesting: we measured a maximum power draw of 150 watts, yet it's impossible to feed more than that into the MacBook, even when using a more powerful 180-watt USB-C adapter.
The Battery Drain Dilemma
The consequences of this power limitation are clear: under these extreme conditions, the MacBook Pro 16 loses approximately 12% of its battery charge within just one hour. That's a significant drain for a laptop that costs well over €3,000 in many configurations.
Our Full In-Depth Review
For a comprehensive breakdown of the MacBook Pro 16 with the M5 Max, including performance benchmarks, thermal management analysis, and real-world usage scenarios, check out our full review here.
A Question of Expectations
Naturally, some might argue that this is an unrealistic, extreme scenario—that most users won't push their systems to these limits. However, there's a fundamental principle at play here: when you're spending high four-figure sums on a premium high-performance laptop, you should reasonably expect the power adapter to be adequately rated for the system's capabilities. A proper power supply should even have enough headroom to charge the battery somewhat while the system is under heavy load.
Apple's Historical Power Adapter Approach
This isn't entirely unexpected—Apple has historically designed its power adapters with very tight margins. We've seen this pattern before across multiple product lines. What remains a mystery to us is why Apple continues to limit the device's maximum power draw so strictly, especially when the thermal design is already a bottleneck.
The Ageing MacBook Pro Design
Alongside the cooling limitations, this power adapter issue highlights the age of the current MacBook Pro design. With little having changed in this department for several years, it raises questions about whether Apple is keeping pace with the performance demands of its own processors.
For more technical details and the original testing methodology, you can also refer to the original report on this power adapter limitation.
The Bottom Line
The MacBook Pro 16 with M5 Max is undeniably a powerhouse, but it's being held back by power delivery limitations that seem arbitrary and user-unfriendly. If you're planning on pushing this machine to its limits, be prepared for battery drain even when plugged in—or wait for a redesign that might finally address these longstanding issues.
What are your thoughts on Apple's power adapter strategy? Have you experienced similar issues with your MacBook Pro? Let us know in the comments below.
