Smarter charging for longer battery life

Fast charging is a complicated beast that pushes the boundaries with increasing power. Qualcomm’s Quick Charge 5 bundles over 100 W of power, battery and other sensor-sensitive algorithms as well as a healthy dose of downward compatibility for its most powerful and intelligent fast-charging standard to date. It is important that Quick Charge 5 is compatible with the more universally used USB Power Delivery and its PPS variant – which means that it is a standard that should cover all of your modern devices.

We saw a lot of lightning fast charging technologies on the market in 2021, although most of them are pretty hot which is bad for battery life. So can Quick Charge 5 get any better? We tested the 65W charger that comes with the Qualcomm smartphone for Snapdragon Insiders to see how it fares against competing standards.

Quick Charge 5: Comparison of charging speeds

To get a feel for how Quick Charge 5 compares to other standards, I first tested Qualcomm’s smartphone for Snapdragon Insider against a variety of common standards. Here is the overview:

• Fast charge 5: 42 minutes to completion, 45 W max, 38.7 ° C peak
• Fast charge 3: 67 minutes to full, 18 W max, 34.5 ° C peak
• USB power supply PPS: 51 minutes to full, 35 W max, 34.2 ° C peak
• USB power supply: 65 minutes to full, 18 W max, 32.5 ° C peak

As you would expect, Quick Charge 5 is significantly faster than Qualcomm’s older but hugely popular Quick Charge 3 standard. It offers the handset much more power than the old standard – around 45 watts versus 18 watts. It is important, however, that the new standard is not much hotter than the old one, but more on that in a moment. USB PD PPS doesn’t lag far behind Quick Charge 5, and both are faster than the simpler USB Power Delivery standard as the former is capable of delivering a power request above the latter’s 3A limit.

Also interesting is that Quick Charge 5 uses USB PD PPS as the underlying communication protocol, but the phone negotiates higher 17V for 45W of power in Quick Charge 5 mode. USB PD PPS has a lower 9 V, but higher 4 A current for 35 W power. Despite this performance difference, USB PD PPS isn’t much slower than Quick Charge 5 – it’s only in nine minutes, sometimes even less. There are definitely additional proprietary negotiations going on here on top of the protocol, and this affects more than just basic performance negotiation.

The most interesting thing about Quick Charge 5 is that the smartphone is usage and temperature conscious for the implementation of Snapdragon Insiders. When charging with Quick Charge 5, the charger delivers up to 45 W (16.7 V, 2.67 A) of power as long as the screen is off and the temperature stays below about 38 ° C. Once this limit is exceeded or the phone is used while charging, the charger will reduce the power down to 18 W (15.8 V, 1.16 A) until the temperature drops to a lower level. Interestingly, the peak power switches to 15W and a lower voltage (8.7V, 1.77A) as soon as the battery reaches 85% and then drops almost to 5W. Because of this, it takes so long to complete charging after it reaches 99%.

Related: The best mobile phone charging accessory

Temperature- and usage-conscious charging is obviously very beneficial for the life of the battery, as it keeps the cell below the glowing 40 ° C limit and closer to the slightly less uncomfortable 35 ° C limit. We were concerned about other very fast charging technologies that were pushing the battery temperature way beyond these limits, but competing technologies charge faster as a result. However, after an initial quick bump, the yo-yo’s charging power spends most of its time at 30W or less. Because of this averaging of the charging power, Quick Charge 5 is not much faster than USB PD PPS in this example, although it offers a higher maximum power.

A disadvantage of this technique is that the charging power and speed vary somewhat. I measured the phone’s full charge between 42 and 53 minutes, the latter being closer to Qualcomm’s official figure. I find the system a bit oversensitive as it is enough to simply wake up the phone to check a notification to drop the charging performance dramatically and it will take some time to recover. I’ve plotted three QC5 charge cycles in the graph below to show how this affects charge time and battery temperature, and you can clearly see the inconsistent charge time as the power adjusts up and down.

A similar behavior can be observed with Quick Charge 3.0 and USB Power Delivery, although not to the same extent. The two reduce their power when the screen is switched on from 18 W to 12 W. But the standard is initially slower and cooler, so this doesn’t seem anywhere near necessary.

This behavior is not observed when charging via USB Power Delivery PSS. Power peaks at the lower 35W (8.7V, 4.0A) and decreases as the phone charges, resulting in much less heat at first. The charging temperature only reached 34.2 ° C. The interesting thing here is that USB PD PPS offers almost twice the performance of Quick Charge 3, but hits the maximum at roughly the same temperature.

Quick Charge 5 compared to other charging standards

Here, at Android authority, we tested some ultra-fast charging standards and were a little concerned that so many of them would raise the battery temperature well above 40 ° C for long periods of time. These include OnePlus’s 65W Warp Charge, Xiaomi’s proprietary 120W technology and, to a lesser extent, Infinix’s 160W concept phone. In general, the faster you want to charge your phone, the more power it will take, which will result in more heat.

As you can see from the results above, Qualcomm’s 65W Quick Charge 5 is significantly cooler than other fast charging technologies, but it takes a little longer to fill a battery and lasts at least 50% as long as 65W Warp Charge. The different battery capacities are obviously not taken into account, so the temperature measurements are more interesting. Quick Charge 5 is 5 ° C cooler in terms of maximum and average temperatures compared to the hottest competition. In addition to temperature-conscious charging performance, Quick Charge 5 uses new, efficient power management ICs that can be used in dual mode for heat dissipation, although it is not clear whether the smartphone uses this configuration or not for Snapdragon insiders.

I also calculated the average charge speeds per minute for these devices to give an indication of how fast these technologies would work with similar battery capacities.

• Fast charge 5 65W: 95 mAh / min, 38.7 ° C peak, 34.7 ° C ave
• USB-PD PPS 35W: 78 mAh / min, 34.2 ° C peak, 31.7 ° C ave
• OnePlus 65W: 155 mAh / min, 43.2 ° C peak, 39.7 ° C avg
• Xiaomi 120W: 214 mAh / min, 43.8 ° C peak, 39.2 ° C avg
• Infinix 160W: 363 mAh / min, 41.9 ° C peak, 37.9 ° C ave

A limitation of this quick calculation is that the battery composition contributes to the current draw and peak temperature as well as to the discharge characteristics. For example, the Infinix Concept Phone’s expensive 8C battery helps it get a fast charge speed with slightly lower temperatures than its competitors.

That said, Quick Charge 5 is slower regardless of the phone’s battery size, as is USB Power Delivery. But both standards run much cooler on average than the fast proprietary technology we tested, and this ensures longer peak battery life. If it’s just a few minutes difference in charging times, it’s better to go on the side of a cooler battery.

Quick Charge 5: The Verdict

Qualcomm’s Quick Charge 5 is the fastest Quick Charge implementation yet, but it’s still a more conservative standard than other ultra-fast charging technologies hitting the market – although that’s not necessarily a bad thing. It expands the USB Power Delivery PPS standard with the potential for faster charging speeds, at least in the implementation of smartphone for Snapdragon Insiders that I tested. More importantly, temperature and usage-conscious functions ensure that the battery stays below 40 ° C during fast charging, an important marker that other standards are only too happy to ignore in their pursuit of faster charging times.

Today’s tests really summarize the current crossroads in the fast charging market. On the one hand, brands with extremely powerful solutions are striving for ever faster loading times. To do this safely, however, expensive battery and circuit components, more powerful chargers, and all too often proprietary standards are required. Even the best standards exceed the limits of ideal battery temperatures. On the other hand, there are the slower but more universal standards like USB Power Delivery. Their universal nature makes them slower to take advantage of the latest and greatest fast charging solutions, but they are very safe and run cooler than the competition.

Quick Charge 5 falls somewhere in between, maintaining compatibility with popular standards while adding additional features that its partners can leverage in their pursuit of lower temperatures and / or higher speeds. So is Quick Charge 5 any good? Necessarily. In fact, it’s one of the better fast charging standards available in cell phones right now.