[Samsung Galaxy S7 Guides, News, & Discussion] Pilz:
Method:

First I used my phone until the battery was below 15% in order to get a better picture of what the charging would look like over almost a full battery cycle. I did not start at the same battery percentage for each test because I did not find any benefit to doing so. I original did this for uniformity, but it did not make a difference after trying it using the more accurate equipment.

I then cleared my history in the Battery Monitor Pro Widget (BMW Pro) recording app which was used to log the battery [mV], battery temperature [F], time, and battery percentage changes. Once this was done I plugged in my USB Power Monitor, turned airplane mode on, removed the case, and let the phone charge. I started logging the data via my power monitor once the phone showed it was charging. From this point onward I let the phone charge without interrupting it until it reached 100%, then I let it charge for another 10-60 minutes to see if it was still drawing power from each charger. Once all of this was done, I exported my data collected from BMW Pro, emailed it to myself, and pasted it along with the USB Power Monitor data into an Excel spreadsheet. All of the data was then delimited to separate the clusters of data due to the way they were recorded, and subsequently graphed. The USB Power Monitor recorded data points every 0.36 seconds, while the BMW Pro took recordings every 5 seconds because I was having issues with the “real-time” recording option in the app working correctly.

All of the data was then graphed into the nice figures you will see below; each color reflects the same variable across all of the graphs to make reading them easier. I included a legend at the top of each set of graphs which should also help make it easier to read the data.

The most interesting part of this test is how cool the S7 Edge stays while charging, and the very marginal difference in overall charging time between QC 2.0/1.0. A 15-minute gap is marginal at best given the ‘big improvements’ Qualcomm claimed when launching the newer standards.

When conducting the wireless charging tests I think there is some error in the Samsung Fast Wireless charging data, so I plan on redoing it at some point. I already redid the Choetech one because it has a similar strangely long, but now it seems more in line with what I initially found before using the newer testing equipment.

I wanted to also quickly point out that both my HTC 10 and S7 Edge keep pulling current even after the phones show they are 100% charged. I’m not talking about a tiny amount; they both pulled ~1-5W+ after hitting 100% battery which is A LOT considering they are reporting to be fully charged. I verified this using 3 multimeters just to be sure. It appears as if Qualcomm, or the OEM’s are falsely reporting when the phone is actually charged, or there’s some other shady things going on here.

Another thing I wanted to mention is how the S7 Edge is so consistent in the way it charges the battery. It could be due to the lower rates Samsung uses (9V/1.67A max which is 15.03W) vs the HTC 10’s up to 18W that I’ve seen it pull. Just take a look at how the S7 Edge charges using QC 2.0 compared to the HTC 10 with lower temperatures, similar times, and a much more consistent overall charging curve.

If you look at the Tronsmart & Choetech QC2.0 tests, then you might notice the large difference between the two. The Tronsmart charger has a harder time holding onto the proper voltages, therefore it bounces around more from ~8.92V-9.03V (a 0.11V change) while the Choetech one ranges from 9.077V-9.092 which is a significantly smaller 0.015V range. The power control chip is responsible for controlling these voltages, and clearly the Choetech one has a better chip in it. This is especially important for external battery packs where efficiency really matters due to the limited amount of power they can store.

Equipment:

These tests were conducted using a series of different chargers. The same brand was used for both Quick Charge 2.0/3.0 tests to minimize experimental error; This trend remained the same was also done for the wireless charging tests

Wall Chargers:

Quick Charge 2.0: Tronsmart 18W charger 5V/2A, 9V/2A, 12V/1.5A

Quick Charge 3.0: Tronsmart 18W charger 3.6-6.5V/3A, 6.5-9V/2A, 9-12V/1.5A

USB inline Power Monitor:

XYZ Studio 0-24V, 0-3A USB Power Monitor

Tronsmart 5-12V USB multimeter (not used in this test, but was used in the older version)

Software/App(s):

Battery Monitor Widget Pro

Excel

Notepad++

Realterm (for the USB power monitor logging)

Legend

QC 2.0 Tronsmart S7

QC 2.0 Choetech

QC 1.0 Samsung

Choetech Fast Wireless Charger

Samsung Fast Wireless Charger

Samsung Wireless Charger

Normalized data Table

Full sized downloadable pictures of everything (data wise) you see above.