Comment by Iulioh
8 hours ago
Eh.
A lot of laptops won't accept less than 60w
My work laptop won't accept less than 90w (A modern HP, i7 155h with a random low end GPU)
At first everyone at the office just assumed that the USB C wasn't able to charge the pc
I gotta say, I love my macbooks. Every Apple laptop I've owned that has USB-C ports will happily charge itself from a 5V/1.5A wall charger (albeit extremely slowly).
That hasn’t been my experience. I once tried to charge an M3 MBP via a lower powered wall plug. It was left off over night and the following morning the battery was still at 1%.
Note:
Some devices expect USB-A on the charger side instead of C
USB-A pump out 1A5V(5W) regardless of what's connected to it, then it negotiate higher power if available.
USB C-C does not give any power if the receiving device is not able to negotiate it
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What did it start at?
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They probably require higher voltages but I havent seen one myself. I usually just charge y laptop with my phone charger, what is it, 18 watts? Don't care, charges my laptop and the phone that is plugged into it overnight. Why charge at faster speeds when there is no need to
Laptop charges fine regular 5V as well.
My Thinkpad T490 will happily take any power provided voltage is high enough (15V+).
Great. So we got EU laws to mandate USB-C chargers and then get manufacturers that flaunt the spirit of the law by rejecting lower wattages.
My laptop refuses to charge for 45W chargers as well, but I can almost understand it.
When plugged into 100W chargers while powered on, it takes ten minutes to gain a single percentage point. Idle in power save may let me charge the thing in a few hours. If I start playing video, the battery slowly drains.
If your laptop is part space heater, like most laptops with Nvidia GPUs in them seem to be, using a low power adapter like that is pretty useless.
Also, 100W chargers are what, 25 euros these days? An OEM charger costs about 120 so the USB-C plan still works out.
Other manufacturers do similar things. Apple accepts lower wattage chargers (because that's what they sell themselves) but they ignore two power negotiation standards and only supports the very latest, which isn't in many affordable chargers, limiting the fast charge capacity for third parties.
Which laptop is that? My Razer with 5070 will take 45W chargers just fine, so do the ThinkPads, my work 16" MacBook and previous Asus Zephyrus with 4070.
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A Mac mini at home used 4.64w averaged over the last 30 days. Even under load it just sips power.
It can draw a lot more under load? https://support.apple.com/en-gb/103253
The issue might not be the wattage bit rather the minimum voltage. (Some?) Macs seems to charge at 15v already, most laptops need 20v
Coincidentally, the USB-C spec is written such that wattage implies a minimum set of supported voltages:
* ≤15W charger: must have 5V
* ≤27W charger: must have 5V & 9V
* ≤45W charger: must have 5V & 9V & 15V
* (OT but worth noting: >60W: requires "chipped" cable.)
* ≤100W charger: must have 5V & 9V & 15V & 20V
(levels above this starting to become relevant for the new 240W stuff)
(36W/12V doesn't exist anymore in PD 3.0. There seems to be a pattern with 140W @ 28V now, and then 240W at 48V, I haven't checked what's actually in the specs now for those, vs. what's just "herd agreement".)
Some devices are built to only charge from 20V, which means you need to buy a 45.000001W (scnr) charger to be sure it'll charge. If I remember correctly, requiring a minimum wattage to charge is permitted by the standard, so if the device requires a 46W charger it can assume it'll get 15V. Not sure about what exactly the spec says there, though.
(Of course the chargers may support higher voltages at lower power, but that'd cost money to build so they pretty much don't.)
NB: the lower voltages are all mandatory to support for higher powered chargers to be spec compliant. Some that don't do that exist — they're not spec compliant.
My laptop has
And I can charge it via USB-C using a 22.5W powerbank @ 12V (HP EliteBook 845 G10.)
I guess that would be out of spec then?
edit: nvm I didn't see the qualifier 'minimum'
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Most laptops will take 45W. There might be some workstations that don't, but even gaming stuff with 5080s will charge on 45W.