3 ms·

Let's talk power: The USB-C PD charger of my Nintendo Switch does not charge my phone, but it does charge my Surface. My phone's USB-C charger does charge the

Let's talk power: The USB-C PD charger of my Nintendo Switch does not charge my phone, but it does charge my Surface. My phone's USB-C charger does charge the phone and Surface, but not the Switch. My USB-C battery pack charges my phone, but is charged by my Surface. Yeah, it just works. How do, say, a battery pack and a Surface negotiate who is charging who over a symmetric USB-C-to-C cable?

ben-schaaf 7y ago
On the topic of power, I really don't understand how USB-C is supposed to replace charging cables. USB-C is limited to 100W. That's enough for a switch, phone or low power laptop, but if this[0] is anything to go by the 6 core intel laptop CPUs already eats 80W of power. Add an extra 2 cores and you might not even be able to sustain a CPU load without draining the battery. Not to mention much higher power draw GPUs. My real question here is what's the plan? Because it's not possible to push 200-300W down a USB-C cable. [0] https://www.techspot.com/review/1847-intel-core-i7-9750h-vs-8750h/ https://www.techspot.com/review/1847-intel-core-i7-9750h-vs-...
- MaddAgent 7y ago
  So you're thinking the new MacBook Pro 16 with an 8 Core CPU and a GPU using the included 96Watt USB-C charger may drain the battery under full load?
  - rhinoceraptor 7y ago
    It will drain the battery at full load, the i9 is a 45 watt TDP and the RX 5500M is 85 watt TDP (plus display, ram, disk, etc). However, there's no way the cooling on the laptop can support that much power draw, so I'd expect it to throttle itself way before you'd drain the battery while plugged in.
- rhinoceraptor 7y ago
  Big gaming laptops will always require big power supplies, probably using barrel jacks. I've seen really gigantic ones that use two! But pretty much every other laptop can get away with well under 100 watts. I use a 30 watt USB C charger at home, and it's fine for using my 15" i7/560X MBP at my desk, because I'm not running it at 100% CPU/GPU for extended periods.
seminatl 7y ago
The power adapter that comes with the Switch supports only parts of the usb-pd standard. That’s why it didn’t work with your other phone. You’re absolutely right about the protocol being unreasonable with two batteries connected together. FireWire has the same problem. You could charge a FireWire iPod from its wall adapter, and you could charge one from an iBook. If you accidentally plugged the AC adapter into the FireWire port of the iBook it would destroy the port. Buses where every participant is an equal peer are expensive and complicated.
izacus 7y ago
Nintendo Switch isn't standards compliant with USB-C and as such it's pretty much the same as having any other non-compatible proprietary standard.

ben-schaaf 7y ago

On the topic of power, I really don't understand how USB-C is supposed to replace charging cables. USB-C is limited to 100W. That's enough for a switch, phone or low power laptop, but if this[0] is anything to go by the 6 core intel laptop CPUs already eats 80W of power. Add an extra 2 cores and you might not even be able to sustain a CPU load without draining the battery. Not to mention much higher power draw GPUs. My real question here is what's the plan? Because it's not possible to push 200-300W down a USB-C cable. [0] https://www.techspot.com/review/1847-intel-core-i7-9750h-vs-8750h/ https://www.techspot.com/review/1847-intel-core-i7-9750h-vs-...

MaddAgent 7y ago
So you're thinking the new MacBook Pro 16 with an 8 Core CPU and a GPU using the included 96Watt USB-C charger may drain the battery under full load?
- rhinoceraptor 7y ago
  It will drain the battery at full load, the i9 is a 45 watt TDP and the RX 5500M is 85 watt TDP (plus display, ram, disk, etc). However, there's no way the cooling on the laptop can support that much power draw, so I'd expect it to throttle itself way before you'd drain the battery while plugged in.
rhinoceraptor 7y ago
Big gaming laptops will always require big power supplies, probably using barrel jacks. I've seen really gigantic ones that use two! But pretty much every other laptop can get away with well under 100 watts. I use a 30 watt USB C charger at home, and it's fine for using my 15" i7/560X MBP at my desk, because I'm not running it at 100% CPU/GPU for extended periods.

seminatl 7y ago

The power adapter that comes with the Switch supports only parts of the usb-pd standard. That’s why it didn’t work with your other phone. You’re absolutely right about the protocol being unreasonable with two batteries connected together. FireWire has the same problem. You could charge a FireWire iPod from its wall adapter, and you could charge one from an iBook. If you accidentally plugged the AC adapter into the FireWire port of the iBook it would destroy the port. Buses where every participant is an equal peer are expensive and complicated.

izacus 7y ago

Nintendo Switch isn't standards compliant with USB-C and as such it's pretty much the same as having any other non-compatible proprietary standard.