[LG G5 Guides, News, & Discussion] waylo:
QC3.0 data!

I have been working with 2 QC3.0 wall chargers with USB-A ports over the past couple of weeks. I’ve also purchased a USB voltmeter/ammeter to help with more measurements to understand our charging capabilities.

One charger is the ChoeTech QC3.0 18W USB Wall Charger, available here:

http://amazon.com/Charge-Charger-Co...&redirect=true&ref_=oh_aui_detailpage_o02_s00

The other is the Tronsmart WC1T 18W USB Wall Charger, available here:

http://www.amazon.com/Tronsmart-WC1...rue&ref_=ox_sc_sfl_title_1&smid=ALTVS0Q5KJ7M3

For full disclosure, I received both as free retail products courtesy of each company. They were both delivered via Amazon so they are the same as you’d get if you ordered them yourself.

I purchased for myself a very cheap USB multimeter, available here: http://www.ebay.com/itm/400963912153

It does okay. I then purchased a more reputable Drok multimeter, available here: https://www.amazon.com/DROK-Multime...true&ref_=ox_sc_act_title_1&smid=AFHAE9RJVUMB

Finally, ChoeTech provided a fairly capable USB multimeter of their own manufacture for my testing purposes.

Once again, my talking points first. Then a bunch of nitty gritty details afterwards if you so care.

1. Both QC3.0 chargers are made well and supply variable voltage, the main difference between QC3.0 and QC2.0.

2. The charging times for QC2.0 and QC3.0 are nearly identical!

3. The voltage used to attain these charging times, however, is much lower in QC3.0 than QC2.0. This will help with battery longevity.

4. We do NOT get the 80% in 35 minutes charging that is sometimes touted in QC3 ads. More like 65%. There are some reasons for this.

5. USB-C specification compliant USB-A to USB-C cables DO NOT limit our QC3.0 phone to 5V and 2.4A. This is safe per Qualcomm.

6. Our G5 phones seem to like ~6.5-7.0V charging voltage when used with a QC3.0 adapter. With our LG QC2-ish fast adapter it stays around 9V the whole time.

First, some relevant technical info re: USB-C standards vs QC3.0 charging.

QC3.0 is by definition not compliant with USB-C standards, because variable voltage is not allowed by the USB-C specification. So Nexus USB-C’s charging, which is adherent to USB-C spec, is not the same as Qualcomm QC3.0. You may have heard of Benson Leung, the Google engineer, who has set out to test USB-C devices and accessories. He does not endorse the G5 or the HTC 10 because they do not completely adhere to USB-C spec, but rather Qualcomm’s QC3.0.

Just because the cables are not USB-C spec does not mean that they are unsafe. To me, it really just means that USB-C spec devices may not be able to properly draw current from a power source when using a non-spec USB-C cable, which could damage the power source. Not exactly relevant to Qualcomm’s QC3.0. In fact, Qualcomm put out a statement to qualify this: http://www.androidcentral.com/qualcomm-addresses-usb-type-c-and-quick-charge-30-compatibility

The USB-C specs become a bit relevant when talking about USB-A to USB-C cables and adapters. Due to the circuitry required to make these spec, these cables and adapters are limited to 5V @ 2.4 A when used by USB-C spec devices. All the ones that Amazon sells now are USB-C standard compliant.

Based on my testing, however, this limitation does NOT extend to QC devices. We definitely get > 5V on my voltmeter testing. This was using both the LG-supplied USB-A to USB-C cable, as well as a Benson-approved USB-A to USB-C cable. The amperage measured with the USB volt/ammeter does not typically go >2.5A however. This may be more a reflection of the wattage rating of the chargers. They top out at 18W, and wattage = voltage * amperage. The top amperage their stats spout is 3A.

With the supplied LG fast charger (QC2.0-esque), it will hang out at 9V the entire time with the amperage starting out around 2A and then dropping as the battery fills.

I had stated previously in many places that the amperage tops out around ~3A early in the charging process, which is from data collected via the app Battery Monitor Widget (BMW). This is incorrect, due to the way the Android OS reports amperage. I have been informed that the Android OS amp data is based on 5V charging, so anything different from that (as we would see on QC2 and QC3) can result in erroneously high amperage readings.

I do not know if the LG supplied cord is spec because I do not have the equipment needed to test it (basically just a Nexus and the CheckR app). But I will be incorporating it into our test data to show you how it compares.

Here's a snapshot of the relevant stats printed on the adapters, with the Tronsmart on the left and the ChoeTech on the right:

One notable difference is that on the Tronsmart, the voltages are printed as variable, which is one of the major improvements to QC3.0. Interestingly, on the ChoeTech there is no mention of variable voltage. In my testing it does vary the voltage similarly, but my personal opinion is they are missing out by not advertising this on the label.

Other notable pros/cons:

1. The ChoeTech has a reversible USB-A port, so it doesn't matter which end is up. That's nice. It also comes with a USB-A to USB-C cord, though only 3 feet long.

2. The ChoeTech cable supplied is the same USB-A to C cable which has been reviewed and approved as USB-C spec by Benson Leung here: http://www.amazon.com/review/R3URN3...sb-20&linkId=9f4d7368af5d896b0482e4f62db75d06

ChoeTech support has confirmed this personally.

3. The TronSmart comes with a longer cord, but unfortunately it’s USB-A to micro-USB. It’s too bad it’s micro-USB, because I’m not aware of any QC3 phones that use microUSB. So you’ll need an adapter or a different cord.

First up, the ChoeTech.

[MENTION=3471230]stuart0001[/MENTION] has posted an earlier review of the ChoeTech UK version, seen here: http://xdaforums.com/lg-g5/accessories/choetech-qc-3-0-18w-wall-charger-t3356038. Interestingly, he found that the charge rates were exactly the same as his LG fast charger if the screen was off. There were some situations were QC3 charging was much better with the screen on at high temperatures.

For the first ChoeTech test run, I used the LG-supplied cable.

Top off amperage was applied for an additional 30-40 minutes after hitting 100%.

I repeated this with the ChoeTech Benson approved cable and found identical results.

Onto the Tronsmart. I used the G5 supplied LG cable first.

Repeating the cycle with the ChoeTech Benson approved cable gave nearly identical data.

Comparing side by side by side the QC2.0 data with the QC3.0 data:

So very intriguing. Just like with [MENTION=3471230]stuart0001[/MENTION] 's analysis, the charging times did not differ much at all from QC2.0 charging!

But there’s more to this than just the charging times. Using my voltmeter, the voltage for each charger is a bit different. Using the LG fast adapter, the voltage hangs around 9V for the entire duration with the amperage slowing decreasing.

Using QC3.0, voltage ranged between 6.3 - 8.3V, with amperage maxing at 2.7A.

(Note the nonstandard charging time data points. The voltmeter does not have any logging capability, so I physically had to check on it throughout the hour+. Sometimes I had things to do :p)

QC3.0 advertises 80% fill in 35 minutes for QC3.0, compared with 65% for QC2.0. We don’t really see this though. Possible reasons?

1. The phone has preset charging parameters that won’t let us go that fast. A Tronsmart support person has told me that the G5 likes 6V as its optimal charging level. We do see this on the voltmeter results much of the charging cycle. I believe this is set in the kernel programming.

2. The 18W rating on the chargers tested won’t allow for greater amperage or voltage. There are 24W chargers out there.

3. The USB-A port on the chargers have some limit? Would love to test a USB-C port QC3.0 charger (I think there’s only one on Amazon right now).

4. There is some sort of charging limitation in the USB-A to USB-C cable after all.

More ideas to think about.

EDIT:

Attempts to monitor charging voltage/amperage of the USB-A to micro-USB with USB-C adapter result in repeat disconnects and reconnects.

I think the amperage and voltages are too high for the connected USB meter to measure and pass through.

EDIT 2:

I purchased a more reputable USB meter and it works now. The cheap one would throw a fit and reset/cut off charging when the voltage or amperage hit its upper limits. I may re-test some of the voltage measurements in the future.