USB Power Delivery: The fastest way to charge your iPhone and Android device

The latest generation of iPhone and Android hardware supports the fastest charge technologies possible. Don't just use the cable and charger that comes in the box.

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Anker 28600 With USB PD

With the introduction of the iPhone 8 and now the iPhone XS/Max and soon to be delivered XR, with their much faster processors and vivid high-resolution displays and always-on connectivity, demands on battery performance are now higher than ever before.

As a recent owner of one of these devices, you may have noticed that while you are on the road, you're running out of juice quickly. So you're probably going to need to invest in a portable battery and a faster wall charger.

Also: Here's how much it costs to charge a smartphone for a year

But not all portable batteries are the same, despite the fact that they might use similar Lithium Polymer (LiPo) and Lithium Ion (Lion) cells for capacity and look very much alike.

Modern smartphone hardware from Apple and various Android manufacturers support much faster charging rates than what was previously supported.

But if you use the charger that comes in the box with the current generation iPhone hardware, or if you just simply buy just any portable battery pack on the market, you're going to be disappointed.

Ideally, you want to match your charger, battery and even the charging cable to the optimal charging speeds that your device supports.

There are three different high-speed USB charging standards currently on the market, and while all of them will work with your device using a common legacy charge mode, you will ideally want to match up the correct technology in order to optimize the speed in which you can top off your phone, tablet, or even your laptop.

Let's start by explaining the differences between them.

Legacy USB-A 2.0 and 3.0 charging

If your Android device has the USB Micro B connector (the dreaded fragile trapezoid that's impossible to connect in the dark) you can fast charge it using an inexpensive USB-A to USB Micro B cable.

If the device and the charge port both support the USB 2.0 standard (pretty much the least common denominator these days for entry-level Android smartphones) you can charge it at 1.5A/5V.

Also: How I learned to stop worrying and love USB Type-C

Some consumer electronics, such as higher-end vape batteries that use the Evolv DNA chipset can charge at 2A.

A USB 3.0/3.1 charge port on one of these batteries can supply 3.0A/5V if the device supports it.

If you are charging an accessory, such as an inexpensive pair of wireless earbuds or another Bluetooth device, and it doesn't support either of the USB-A fast charging specs, it will slow charge at either 500mA or 900mA which is about the same you can expect from directly connecting it to most PCs.

Mode Voltage Max Current Connector
USB PD Variable up to 20V 5A USB-C
USB Type-C 3A 5V 3.0A USB-C
USB Type-C 1.5A 5V 1.5A USB-C
QC 4.0 (USB-PD Compatible) Variable up to 20V 4.6A USB-C
QC 3.0 Variable up to 20V 4.6A USB-A/USB-C
QC 2.0 5V, 9V, 12V, 20V 2A USB-A
USB BC 1.2 5V 1.5A USB-A
USB 3.1 5V 900mA USB-A
USB 2.0 5V 500mA USB-A

Many of the portable batteries on the market have both USB-C and multiple USB-A ports. Some of them have USB-A ports which can deliver the same voltage, while others feature one fast (2.4A) and one slow (1A).

So you will want to make sure you plug the device into the battery port which can charge it at the fastest rate if you want to top off the device as quickly as possible.

USB Power Delivery

USB Power Delivery (USB PD) is a relatively new fast charge standard which was introduced by the USB Implementers Forum, the creators of the USB standard.

It is an industry-standard open specification that provides high-speed charging with variable voltage up to 20V using intelligent device negotiation up to 5A at 100W.

It scales all the way up from smartphones to notebook computers provided they use a USB-C connector and a USB-C power controller on the client and host.

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Sample charging times using USB PD technology (Source: Belkin)

Batteries and wall chargers which employ USB PD have the ability to charge devices up to 100W output using a USB-C connector -- however, most output at 30W because that is on the upper range of what most smartphones and tablets can handle, whereas laptops require adapters and batteries that can output at a higher wattage.

Apple introduced USB PD charging with iOS devices with the launch of the 2015 iPad Pro 12.9" and with OS X laptops in the MacBook Pro as of 2016. The iPhone 8, the iPhone X and XS/Max can rapid charge with USB PD using any USB PD charging accessory -- you don't have to use Apple's OEM USB-C 29W or its 61W power adapters -- but it requires that you use Apple's OEM MKQ42AM/A (1m ) or MD818ZM/A (2m) USB-C to Lightning cables which unfortunately are a tad expensive at around $19-$35 from various online retailers.

Personally, I buy mine from Amazon but your mileage may vary.

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Apple OEM USB-C to Lightning Cable. The only fast charge cable for iPhones that currently works.

There are cheaper 3rd-party USB-C to Lightning cables, but none of the ones we have tested on the market will charge current generation iOS devices at full speed -- they can't do better than 2.4A because Apple uses a special integrated circuit in their cables for power negotiation.

We are expecting to see 3rd-party MFI-certified USB-C to Lightning cables -- hopefully less expensive than Apple's OEM cable -- by the end of Q4 of 2018, so watch this space.

We would also like to mention Belkin because although they do not have a USB PD battery solution or MFI-certified USB-C cables yet, they do have some excellent USB PD wall charging and 12V car charger solutions which are much more cost-competitive than the OEM Apple 29W USB-C charger.

Qualcomm Quick Charge

Qualcomm, whose Snapdragon SoCs are used in a number of popular smartphones and tablets, has its own fast-charging standard, Quick Charge, which has been through multiple iterations.

The current implementation is Quick Charge 4.0 which is backward-compatible with older Quick Charge accessories and devices. Unlike USB PD, Quick Charge 2.0 and 3.0 can be delivered using the USB-A connector. Quick Charge 4.0 is exclusive to USB-C.

Quick Charge 4.0 is only present in phones which use the Qualcomm Snapdragon 835/845 which can be found in the US version of the Samsung Galaxy S9 and Galaxy Note 9, OnePlus 6, HTC U11, LG V30, Moto Z2 Force, the Google Pixel 2 XL and upcoming Pixel 3 XL.

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RavPower 26000mAh with Quick Charge 3.0

ZDNet

The Xiaomi Mi 6, Xiaomi Mix 2, ZTE Nubia Z17, and the Sony Xperia XZ Premium also use QC 4.0, but they aren't sold in the US market currently. Huawei's phones utilize their own Kirin 970/980 chips which use their own Supercharge standard but they are backward compatible with the 18W USB PD standard.

Like USB PD, QC 3.0 and QC 4.0 are variable voltage technologies and will intelligently ramp up your device for optimal charging speeds and safety. However, Quick Charge 3.0 and 4.0 differ from USB PD in that it has some additional features for thermal management and voltage stepping with the Snapdragon 820/821/835/845 in order to optimize for reduced heat footprint while charging.

Also: The 6 best portable battery chargers for smartphones and tablets TechRepublic

It also uses a different variable voltage selection and negotiation protocol than USB PD which Qualcomm advertises as better/safer for its own SoCs.

And for devices which use Qualcomm's current chipsets, Quick Charge 4.0 is about 25 percent faster than Quick Charge 3.0. The company advertises five hours of usage time on the device for five minutes of charge time.

However, while it is present in (some of ) the wall chargers that ship with the devices themselves, and a few 3rd-party solutions, Quick Charge 4 is not in any battery products yet. The reason for this is that it is not just competing with USB Power Delivery, is also compatible with USB Power Delivery.

Qualcomm's technology and ICs have to be licensed at considerable additional expense to the OEMs, whereas USB PD is an open standard.

If you compound this with the fact that Google itself is recommending OEMs conform to USB-PD over Quick Charge for Android-based products, it sounds like USB PD is the way to go, right?

Well, sort of. If you have a Quick Charge 3.0 device, definitely get a Quick Charge 3.0 battery. But if you have a Quick Charge 4.0 device or an iOS device, get at USB PD battery, for now.

Which Battery?

Now that you understand the fundamental charging technologies, which battery to buy?

Vendor Model Tech Capacity
/mAh
Port 1 Port 2 Port 3 Port 4 MSRP
RavPower RP-PB058 USB PD 26800 USB-A USB-A USB-C (30W) USB-Micro-B (Input) $79.99
Anker PowerCore+ 26800 PD* USB PD 26800 USB-A USB-A USB-C (30W) * $119.99
RavPower RP-PB043 QC 3.0 20100 USB-A USB-A (QC 3.0) USB-C (18W) USB-Micro-B (Input) $49.99
RavPower RP-PB059 USB PD 20100 USB-A USB-A USB-C (30W) USB-Micro-B (Input) $69.99
Anker PowerCore Speed 20000 PD* USB PD 20100 USB-A USB-C (30W) * * $99.00
Anker PowerCore II 20000 QC 3.0 20000 USB-A (18W) USB-A (18W) * * $49.99
Mophie Powerstation USB-C XXL USB PD 19500 USB-A USB-C (30W) * * $149.95
Mophie Powerstation Plus XL USB PD 12000 USB-A (15W) USB-C (18W) * * $99

* Two Anker models -- PowerCore+ 26800 PD and PowerCore Speed 20000 PD -- are the only two models to include a wall charger.

We've tested a bunch of these and we've essentially narrowed it down to two: The RAVPower RP-PB058 for USB PD (newest iPhones and newest Androids) and the Anker PowerCore+ 26800 for Quick Charge 3.0 (Previous generation Androids). Both are 26800mAh batteries with huge charge capacity.

Also: Mophie 30-day wireless challenge: Staying powered up without a cable connection

Anker's product is more expensive but it comes with a USB-C QC 3.0 wall charger that can be used with the battery or direct charge a QC 3.0 compatible device, whereas the RAVPower we have seen on the street as low as $60 with wide market availability and with Amazon Prime promotions, so be sure to shop around because that is a great value at that price.

Anker also has a USB PD version of the PowerCore+ 26800 bundle but it is not as easy to find. We suspect the company is working on a new product revision compatible with USB PD and QC 4.0 and it will be out after the holidays -- but if you see the current model on sale, jump on it. We particularly like the metal case design and the large illuminated power stud button that is easy to feel even in the dark.

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ZMI 20000 USB PD

ZDNet

Both of these companies sell equivalent USB PD and QC 3.0 products including compatible wall chargers (see Anker and RavPower). As with Apple's own OEM accessories, it isn't necessary to match brands when pairing a wall charger with a USB PD or QC 3.0 battery.

However, because of licensing, the QC 3.0 ones appear to be priced more expensively -- so unless you have a QC 3.0 compatible device, we suggest you stay with USB PD charging accessories for now.

A product that we did not mention in earlier drafts of this article is the ZMI 20000 mAh USB PD Backup Battery which along with its USB PD wall charger is currently on promotion at Amazon.

If you buy both of these products together, Amazon will apply a promotional discount, which makes the combined price $89.90 which is less than what Anker and RavPower offer their equivalent battery/charger bundles for.

Also: Mophie Powerstation Plus XL and XXL portable batteries: One Lightning cable to rule them all

This particular product has the distinction of having both USB PD and QC 3.0 capabilities, has a 45W USB PD output for charging everything up to laptops, and can also act as a daisy-chained USB 2.0 hub, so it is a particularly good buy. ZMI makes OEM products for Xiaomi, a huge Chinese smartphone manufacturer which like Huawei, has yet to find US carrier distribution yet.

Two other products we would like to mention are the Mophie Powerstation USB-C XXL and the Mophie Powerstation AC.

The USB-C XXL is a very nice looking battery as it integrates a fabric wrap over the polycarbonate casing so it's pleasant to the touch -- and it fully supports USB PD at 30W.

Its big brother is the Powerstation AC, which in addition to a USB-C PD and USB-A port, also has a 110VAC/100W port to supply power to virtually anything that uses standard 110V plugs, including legacy laptops and other electronic devices.