Can the USB-C charger for MBP 16" be used to charge a Yoga C940 15"?

hajime

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Jul 23, 2007
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Please note that the 14" and 15" are very different machines. I am talking about the 15" one with i9 and 4K LCD.
 

Infinite Vortex

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Mar 6, 2015
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Yes. In fact pretty much any USB-C PD charger can charge any USB-C PD device. That is, I can charge my MBP from the 15W charger from my smartphone and I can charge from smartphone from my MBP charger just the same. Charge times though will vary based on wattage.

In fact for short trips, like a weekend getaway, I will use the far more compact and convenient 45W charge for a Samsung Galaxy Note 10 for my MBP (and phone and tablet) instead of the MBP charger. I even take to Apple 2m cable and will use the shorter cable to go from the MBP to my phone/tablet. While less than the usual 60W it's plenty to charge my MBP which can itself charge both my phone and tablet via USB-C PD cables.
 

hajime

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Users have reported that they cannot charge the device using usb-c adapters and there are talks that usb-c charging is disabled for the 15" version by Lenovo. I don’t know if this makes sense. Is it just like the iPad Pro, the higher the Watt, the faster the charging at the cost of some heat? Is there a potential of hazard for charging via usb-c on a laptop that is not MBP 16"?
 

Infinite Vortex

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Mar 6, 2015
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The device itself won't charge any faster, and hence not get any hotter, than what it is originally capable of. For instance, if I plug my phone that can go at 15W into a 100W charger it is still only going to get 15W of power at most. USB power delivery is standard across the board so in theory it should all be mix & match. If you have problems with charging your Lenovo via USB-C I would consult a Lenovo site as you're not going to get any help here other than "it should work".
 

hajime

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Jul 23, 2007
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The device itself won't charge any faster, and hence not get any hotter, than what it is originally capable of. For instance, if I plug my phone that can go at 15W into a 100W charger it is still only going to get 15W of power at most. USB power delivery is standard across the board so in theory it should all be mix & match. If you have problems with charging your Lenovo via USB-C I would consult a Lenovo site as you're not going to get any help here other than "it should work".
Lenovo forum moderators are censoring discussion about using 3rd party chargers on their laptops.
 

Queen6

macrumors 604
Users have reported that they cannot charge the device using usb-c adapters and there are talks that usb-c charging is disabled for the 15" version by Lenovo. I don’t know if this makes sense. Is it just like the iPad Pro, the higher the Watt, the faster the charging at the cost of some heat? Is there a potential of hazard for charging via usb-c on a laptop that is not MBP 16"?
I think you should charge the Lenovo with the charger it came with it and be done with problems. USB C to USB C charging is and remains problematic between varying manufacturers. Reputable battery's and chargers will only charge at their given rate and will only charge faster if safe to do so.

Powerful notebooks require a lot of power, if an issue purchase additional chargers. I don't know what the Lenovo pulls, however my Asus has a 230W charger and I wouldn't consider charging it via USB C as the charger will be maxed out all to often, temperatures will soar.

If Lenovo has disabled charging via USB C then it's no longer USB C, as that's the point of a standard.

Q-6
 
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hajime

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I think you should charge the Lenovo with the charger it came with it and be done with problems. USB C to USB C charging is and remains problematic between varying manufacturers. Reputable battery's and chargers will only charge at their given rate and will only charge faster if safe to do so.

Powerful notebooks require a lot of power, if an issue purchase additional chargers. I don't know what the Lenovo pulls, however my Asus has a 230W charger and I wouldn't consider charging it via USB C as the charger will be maxed out all to often, temperatures will soar.

If Lenovo has disabled charging via USB C then it's no longer USB C, as that's the point of a standard.

Q-6
Mine came with a 135W AC Adapter. If I use the dGPU, USB-C charger will not work. However, when I do basic office productivity, I am hoping to have a lighter charger. So far, nobody has found a USB-C charger that can charge this laptop. So for safety reason, better to use the charger which came with the laptop? It is 0.49kg.

 

jaytv111

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Oct 25, 2007
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If Lenovo forum users say it doesn't work then it probably doesn't work. The laptop charger it came with is the one safe bet since it's built for it. Not all laptops take USB-C charging when they have USB-C, in fact, on the PC side, many laptops reject certain chargers, some even require their own brand, like I heard HP makes you use HP USB-C chargers on some models (maybe not all). It's also made worse by the spec only allowing 100 watts, so laptops like yours that use more power can't really use USB-C without throttling things like CPU and GPU down (though Dell has a proprietary implementation that ups the available power to like 130 watts). Apple has even chosen low power GPUs on purpose to keep the power draw low enough for USB-C, to the detriment of past 15 inch Macbook Pros having lower GPUs than comparable Windows machines.

Usually lower power machines (ultrabooks and tablets) with USB-C would be fine though with most USB-C chargers, since they have a low power draw and the 30 watt chargers are widely available and provide plenty of power for ultrabook machines.
 
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hajime

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So the best action is to forget about it and use the charger that came with it? I heard that even for the 14", not all chargers work.

One Anker staff told me that their 60W PowerPort Atom III would work but another staff said no.
 

jaytv111

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Oct 25, 2007
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You could try it out. At worst, it doesn't work. At best, it charges slower and possibly throttles the CPU and GPU in a high-load situation. It won't break it or anything if you try it out and it's not compatible, it will just simply do nothing.

If you're saying you want to buy such a charger just for this laptop, then I would say it's not a good idea. If other forum users say it doesn't work then it probably doesn't work. Maybe they're mistaken, maybe not. Find a friend with a Macbook Pro 15 inch and try out their 87 watt charger if you want to try it out without buying a whole charger.
 
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compwiz1202

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May 20, 2010
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Not totally sure, but is it that if the input device doesn't support any of the output voltages of the charger, it won't charge? Or is there more to it?