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USB PD vs. QC 3.0 (QC4.)?

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By andygold, Senior Member on 23rd July 2018, 08:01 PM
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I just purchased an LG G7 ThinQ on Verizon in the US, coming from an LG Optimus G Pro, purchased in 2013. It's being shipped right now, so I don't have it to play with.


With that said, I'm a newbie to quick charging. I see that the phone comes with a QC 3.0 block, and that the phone is listed as being QC 4.0 compatible, as per Qualcomm's website.


I'm looking to order all new cables and chargers to take advantage of the higher charging speeds that this phone can allow. I'm not understanding though whether I'd be better off buying a car charger that is QC 3.0 or has USB PD. I realize that the USB PD would be the way to go for laptops and larger items, but for our phone, is there any difference? I do realize that I'd need a dual-ended USB C cable for the PD charger.


Also, has anyone tried using a QC 4.0 charger on the phone, and although Qualcomm says the phone has the 4.0 hardware, has LG enabled us to use it?
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24th July 2018, 12:40 AM |#2  
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So the LG chargers can deliver 9v 1.8A.

The phone will recognize my 18w and other 45w PD charger, but I haven't managed to see any difference in the charging speeds, and more annoying, charging is pretty slow when screen is on.

I wanna buy a USB meter (PD compatible) to see what's the phone actually asking for, but I assume that it just sits at 15w max.

The reason I have a PD charger is because it allows you to have longer USB-C cables and it's compatible across more devices, like I can fast charger my Huawei Mate 10 pro with it, you can also charge iPhones with it.
24th July 2018, 05:30 AM |#3  
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Quote:
Originally Posted by andygold

I just purchased an LG G7 ThinQ on Verizon in the US, coming from an LG Optimus G Pro, purchased in 2013. It's being shipped right now, so I don't have it to play with.

This thread could be useful for you too: https://r.tapatalk.com/shareLink?url...3&share_type=t
24th July 2018, 08:03 PM |#4  
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USB PD is an entirely different language than QC 2-4. They negotiate and handle power different from each other. If you plug USB PD into a QC device it should default to 5v, 1 or 2 amp standard charging.

Use only QC 3.0+ equipment. That will get you the rapid charge you're looking for as it speaks the right language for the phone. I dont believe LG has enabled QC4 standards in the firmware although the chip supports it.

LG G7 is also wireless rapid charge, i get an almost QC speed on a 15w ravpower and umdigi wireless pads. Took me a few to find ones that were quality and charged fast. Most of the "10w" chargers dont actually put out 10w so they dont charge fast.

Sent from my LM-G710 using Tapatalk
24th July 2018, 09:52 PM |#5  
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Quote:
Originally Posted by datafoo

USB PD is an entirely different language than QC 2-4. They negotiate and handle power different from each other. If you plug USB PD into a QC device it should default to 5v, 1 or 2 amp standard charging.

Use only QC 3.0+ equipment. That will get you the rapid charge you're looking for as it speaks the right language for the phone. I dont believe LG has enabled QC4 standards in the firmware although the chip supports it.

LG G7 is also wireless rapid charge, i get an almost QC speed on a 15w ravpower and umdigi wireless pads. Took me a few to find ones that were quality and charged fast. Most of the "10w" chargers dont actually put out 10w so they dont charge fast.

Sent from my LM-G710 using Tapatalk

QC 4.0 is actually compatible with Power Delivery, Qualcomm did that in fear that Google would make PD mandatory.

And there can be handshaking between previous QC devices and PD chargers, since the most basic profiles are kind of standard (max 9v 2A).

So in this way I can fast charge a S8, the LG G7 and any other QC device with the PD charger and I can charge other PD and QC devices with my Huawei fast charger power bank (it's based on QC 3 delivering max 9V 2A).
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25th July 2018, 04:28 AM |#6  
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Quote:
Originally Posted by Luinwethion

QC 4.0 is actually compatible with Power Delivery, Qualcomm did that in fear that Google would make PD mandatory.

And there can be handshaking between previous QC devices and PD chargers, since the most basic profiles are kind of standard (max 9v 2A).

So in this way I can fast charge a S8, the LG G7 and any other QC device with the PD charger and I can charge other PD and QC devices with my Huawei fast charger power bank (it's based on QC 3 delivering max 9V 2A).

Funny i was just reading an article about that. I suspect that would be a firmware compatibility issue again, as in: did LG enable it.

Great feedback and perfect timing

Sent from my LM-G710 using Tapatalk
25th July 2018, 09:17 AM |#7  
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Quote:
Originally Posted by datafoo

Funny i was just reading an article about that. I suspect that would be a firmware compatibility issue again, as in: did LG enable it.

Great feedback and perfect timing

Sent from my LM-G710 using Tapatalk

I just wished that phones would support higher charging rates via the PD standard.

I'm mostly sure that neither the S8 nor the G7 are taking full advantage of the max power output of their charger for long.

I thought that the charger might be under delivering, but connecting my PD 18w charger results in the same situation, I still need to measure it (need to buy a USB meter to have more details).

But using the same 18w PD charger I can charge the Mate from 20 to 50% much faster than I can charge the G7.
21st August 2018, 08:41 PM |#8  
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OP here. Just found this:


https://gtrusted.com/how-fast-the-po...ery-30-and-pps


https://gtrusted.com/review/how-much...power-delivery


https://gtrusted.com/review/lg-g7-thinq
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