Charging Protocol: Quick Charge

Quick Charge (QC) is a proprietary battery charging protocol developed by Qualcomm, used for managing power delivered over USB, mainly by communicating to the power supply and negotiating a voltage.

Quick Charge is supported by devices such as mobile phones which run on Qualcomm SoCs, and by some chargers; both device and charger must support QC, otherwise QC charging is not attained. It charges batteries in devices faster than standard USB allows by increasing the output voltage supplied by the USB charger, while adopting techniques to prevent the battery damage caused by uncontrolled fast charging and regulating the incoming voltage internally. Many chargers supporting Quick Charge 2.0 and later are wall adaptors, but it is implemented on some in-car chargers, and some power banks use it to both receive and deliver charge.

Quick Charge is also used by other manufacturers' proprietary rapid-charging systems.

Details

Quick Charge is a proprietary technology that can charge battery-powered devices, primarily mobile phones, at power levels exceeding the ten watts (5 volts at 2 amps) supported by the basic USB standard, using existing USB cables. The higher voltage available allows more power (watts) to be supplied through wires without excessive heating. As current is lower for the same power if voltage is increased, there is less resistive loss, which becomes significant for longer cables.

Numerous other companies have competing technologies, including MediaTek Pump Express and OPPO VOOC (licensed to OnePlus as Dash Charge), the latter of which supplies higher current without voltage increase, relying on thicker USB wires to handle the current without overheating, as described in VOOC § Technology.

Though not publicly documented, the voltage negotiation between device and charger has been reverse-engineered, and a custom voltage can be manually requested from the charger using a trigger circuit that simulates the negotiation to an end device.

Speed	Efficiency	Versatility
Quick Charge enables charging speeds of up to 0-50 in five minutes, with 100W+ charging power with our new Dual Charge technology.	Charge smartphones and devices up to 10 degrees C cooler, up to 4X faster, and up to 70% more efficiently than with previous solutions.	Our latest Quick Charge technology is backwards compatible with previous generations of Quick Charge while addressing future Android requirements

Ecosystem

Safety

Quick Charge enables a single accessory to address a variety of charging implementations in mobile devices, supporting 250+ mobile devices and 1000+ accessories.

Quick Charge Advanced Charging Subsystem Safety includes 8 levels of voltage protection, 3 levels of current protection, 3 levels of thermal protection and 3 levels of timer protection – All while incorporating USB-input overvoltage protection at 25V and extreme power controls beyond 30V

Quick Charge requires both the power supply and the device being charged to support it, otherwise charging falls back to the standard USB ten watts.
Quick Charge 2.0 introduced an optional feature called Dual Charge (initially called Parallel Charging),using two PMICs to split the power into 2 streams to reduce phone temperature.
Quick Charge 3.0 introduced INOV (Intelligent Negotiation for Optimal Voltage), Battery Saver Technologies, HVDCP+, and optional Dual Charge+. INOV is an algorithm that determines the optimum power transfer while maximizing efficiency. Battery Saver Technologies aims to maintain at least 80% of the battery's original charge capacity after 500 charge cycles.
Qualcomm claims Quick Charge 3.0 is up to 4–6 °C cooler, 16% faster and 38% more efficient than Quick Charge 2.0, and that Quick Charge 3.0 with Dual Charge+ is up to 7–8 °C cooler, 27% faster and 45% more efficient than Quick Charge 2.0 with Dual Charge.
Quick Charge 4 was announced in December 2016 for the Snapdragon 835 and later chips. Quick Charge 4 supports HVDCP++, optional Dual Charge++, INOV 3.0, and Battery Saver Technologies 2. It is cross-compatible with both USB-C and USB-PD specifications, supporting fallback to USB-PD if either the charger or device is not QC-compatible.
However, Quick Charge 4 chargers are not backward compatible with Quick Charge.[citation needed] It also features additional safety measures to protect against over-voltage, over-current and overheating, as well as cable quality detection. Qualcomm claims Quick Charge 4 with Dual Charge++ is up to 5 °C cooler, 20% faster and 30% more efficient than Quick Charge 3.0 with Dual Charge+.
Quick Charge 4+ was announced on June 1, 2017. It introduces Intelligent Thermal Balancing and Advanced Safety Features to eliminate hot spots and protect against overheating and short-circuit or damage to the USB-C connector. Dual Charge++ is mandatory, while in prior versions Dual Charge was optional. Unlike Quick Charge 4, Quick Charge 4+ is fully backward compatible with Quick Charge C 2.0 and 3.0 devices.
Quick Charge 5 was announced on July 27, 2020. With up to 100 W of power, on a mobile phone with a 4500 mAh battery, Qualcomm claims 50% charge in just 5 minutes. Qualcomm announced that this standard is cross-compatible with USB PD PPS programmable power supply, and that its technology can communicate with the charger when charging double cells and double the voltage and current out. For instance, a single battery requests 8.8 supply at V; the dual cell can then ask the PPS charger to output 17.6 volts and split it in half to the two separate batteries, providing 5.6 amps total to achieve 100 watts. The first phone supporting this technology was the Xiaomi Mi 10 Ultra.

Quick Charge for Wireless Power
On 2019 Feb 25, Qualcomm announced Quick Charge for Wireless Power. Quick Charge for Wireless Power falls back on the Qi standard by the Wireless Power Consortium if either the charger or device is not compatible.

Versions

Technology	Release date	Voltage	Maximum		New features	SoCs
Technology	Release date	Voltage	Current	Power	New features	SoCs
Quick Charge 1.0	2013	Up to 6.3V	2A	10Watt	AICL (Automatic Input Current Limit) APSD (Automatic Power Source Detection)	Snapdragon 215, 600
Quick Charge 2.0	2014	Class A: 5V, 9V, 12V Class B: 5V, 9V, 12V,20V	1.67A, 2A, or 3A	18Watt (9V × 2A)	HVDCP (High Voltage Dedicated Charging Port) Dual Charge (optional)	Snapdragon 200, 208, 210, 212, 400, 410, 412, 415, 425, 610, 615, 616, 653, 800, 801, 805, 808, 810
Quick Charge 3.0	2016	3.2 or 3.6V – 20V in 0.2V increments. (inconsistent sources)	2.6A, or 4.6A	36Watt (12V × 3A)	HVDCP+ Dual Charge+ (optional) INOV 1.0 & 2.0 Battery Saver Technologies	Snapdragon 427, 429, 430, 435, 439, 450, 460, 617, 620, 625, 626, 632, 650, 652, 653, 662, 665, 680, 820, 821
Quick Charge 3+	2020	scalable voltage with 20mV steps from Quick Charge 4	?	?	Integrated cable power capability/identification Various safety mechanisms	Snapdragon 765, 765G
Quick Charge 4	2017	via QC: 3.6–20V in 20mV increments via USB PD: 5V, 9V via USB PD 3.0 PPS: 3–21V in 20mV increments	via QC: 2.6A, or 4.6A via USB PD: 3A	via QC: 100Watt (20V × 5A) via USB PD: 27 W	HVDCP++ Dual Charge++ (optional) INOV 3.0 Battery Saver Technologies 2.0 USB PD compatible Cable Quality Detection	Snapdragon 630, 636, 660, 710, 720G, 835, 845
Quick Charge 4+	2017		via QC: 2.6A, or 4.6A via USB PD: 3A	via QC: 100Watt (20V × 5A) via USB PD: 27 W	Dual Charge++ (mandatory) Intelligent Thermal Balancing Advanced Safety Features	Snapdragon 480, 480+, 4 Gen 1, 670, 675, 678, 690, 695, 6 Gen 1, 712, 730, 730G, 732G, 750G, 765, 765G, 768G, 778G, 780G, 7 Gen 1,855, 855+/860, 865, 865+, 870
Quick Charge 5	2020	?	?	>100Watt	>100 W charging power 100% in 15 minutes Better thermal management (not more than 40 °C) Dual Charge	Snapdragon 888, 888+, 8 Gen 1, 8+ 7+ Gen 2