Disclosure: As an Amazon Associate I earn from qualifying purchases. ZMI provided the product in this review.

Tech Specs

Ports:

• USB-C x2
• USB-A

USB-C 1 (Orange) Output:

• 100W USB-C Power Delivery 3.0 (5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/5A)
• 60W PPS (5-11V/3A, 5-20V/3A)
• Quick Charge 3.0
• Samsung Adaptive Fast Charging
• Huawei FCP
• Apple 2.4A

USB-C 2 (Black) Output:

• 45W USB-C Power Delivery x.0 (5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/2.25A)
• 44W PPS (5-11V/3A, 5-20V/2.2A)
• Quick Charge 3.0
• Samsung Adaptive Fast Charging
• Huawei FCP
• Apple 2.4A

USB-A Output:

• 18W Quick Charge 3.0
• Huawei FCP
• Apple 2.4A

USB-A Output w/Xiaomi Cable:

• 100W USB-C Power Delivery 3.0 (5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/5A)
• Quick Charge 3.0
• Huawei FCP
• Apple 2.4A

Multi-port Output:

• 210W total
  • USB-C 1: 100W
  • USB-C 2: 45W
  • USB-A: 65W

USB-C 1 (Orange) Input:

• 100W USB-C Power Delivery 3.0 (5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/5A)

USB-C 2 (Black) Input:

• 45W USB-C Power Delivery 3.0 (5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/2.25A)

Capacity: 25,000mAh | 90.75Wh

Size: 7.4 × 3.2 × 1.1 inches | 188.6 × 80.4 × 27.1 mm

Weight: 1.3 lbs | 580 grams

Model: QB826G

Learn more about Fast Charging.

Included In Box:

• ZMI PowerPack No 20
• USB-C to USB-C cable (USB 2.0, 100W), 1.75 feet/0.5 meter
• Xiaomi proprietary USB-A to USB-C cable, 3.3 feet/1 meter

Good For:

• Additional charger for home or work
• Commute
• Travel
• iPhone
• Android
• Nintendo Switch (handheld & docked)
• iPad Pro
• 12 to 16-inch laptops w/USB-C power

Estimated Number of Charges:

• iPhone 6/7/8/SE: 9 charges
• iPhone X/XR/12: 6 charges
• Samsung Galaxy S8/S9: 5.5 charges
• iPhone 11, Samsung Galaxy S10/S20: 5 charges
• Nintendo Switch (2019): 16 hours of play
• Nintendo Switch Lite: 16 hours of play

First Impression

The ZMI PowerPack No 20 is an all-in-one portable charger for anyone with a range of USB-C devices. It fast charges my iPhone just as well as any size laptop, and all devices in between. Offering capacity over the more common 20,000mAh also allows it to support multiple devices better.

The included USB-C to USB-C cable supports 5A/100W and is short and flexible, which I prefer for travel. The Xiaomi USB-A to USB-C cable is a unique offering but requires you to trust a proprietary standard. All ports are on the same side, are labeled, and the USB-C ports are color-coded to help identify the 100W (orange) vs the 45W (black). The capacity display shows 1-100 clearly.

Compared To Similar Power Banks

Prices are from Amazon Product Advertising API, last updated on 2024-11-21.

You can see more USB-C power banks here.

 

Device Testing

Check with your device’s manufacturer to verify which charging standards it supports.

USB Power Delivery Phones

• Apple iPhone (8 or newer)
• Google Pixel
• Samsung Galaxy (S8 or newer)
• Xiaomi Mi
• Other USB PD supporting phones and tablets

 

Using an iPhone 12 for testing, we find USB PD phones will fast charge over either USB-C port. iPhones will need to use a USB-C to Lightning cable, not included. Android phones can use the included USB-C to USB-C cable.

Quick Charge 3.0 Phones

• Motorola
• Nokia
• Samsung Galaxy (S7 or older)
• Sony
• Most any other Android not supporting USB PD

 

Using a Moto G6 for testing, we see Quick Charge fast charging over the USB-A port.

The two USB-C ports report supporting Quick Charge as well. My particular model Moto doesn’t support QC over USB-C, but newer Android phones likely will.

Nintendo Switch

 

Fast charges all model Nintendo Switch in handheld mode.

• Nintendo Switch (original) – Charges near its max rate while playing and sleeping.
• Nintendo Switch (2019 update) – Charges near its max rate while playing and sleeping.
• Nintendo Switch Lite – Charges near its max rate while playing and sleeping.

It also supports the Switch’s dock, providing enough power for video output to your TV.

Learn more about charging the Switch.

Laptops

 

Using a 13-inch MacBook Pro for testing, we can draw up to 56W from this charger. Expected after accounting for efficiency loss. That’s the max draw rate of my model laptop.

The 100W USB-C port will support up to a 16-inch laptop under any condition.

The 45W USB-C port will support up to a 12-inch laptop, and many 13-inch models.

Multi-Port Output

Aside from the 100W output option, the other big draw for this power bank is its multi-port output capabilities. It can support up to 210W total across up to three devices. Enough to charge three laptops, to say nothing of the mix of devices you travel with.

The two USB-C ports have their own power circuits, which allows them to keep their full output under all conditions. Many other chargers lower the USB-C output when both ports are in use. Here you’ll always get 100W and 45W.

The variable output is on the USB-A port, assuming you’re using the included Xiaomi USB-A to USB-C cable. If just the USB-A port is in use then it offers up to 100W output. But if either (or both) USB-C ports are in use then the USB-A output drops to 65W (20V/3.25A).

100W + 65W + 45W = 210W

If you forgo the Xiaomi cable then you’ll get full output from each port under any condition. With the USB-A then good for Quick Charge fast charging or regular USB-A charging.

Xiaomi Proprietary USB-A to USB-C Cable

I hadn’t heard of this cable until I received ZMI’s power bank. The cable and a proprietary 120W charger are included with the Xiaomi Mi 10 Ultimate/Memorabilia edition. Together they charge the phone’s 4,500mAh battery in 23 minutes. The cable is actually rated for 6A, but with ZMI’s power bank it can only go up to 5A.

Xiaomi made extensive extensions to the USB-A end of this cable. It has CC pins, like a USB-C connector. CC pins are used to establish and manage the connection between the source (charger) and sink (device) with USB-C cables. It is compatible with E-Mark, the system USB PD uses to identify greater than 60W power capabilities between charger and device. Similar changes were made to the USB-A port on ZMI’s power bank, to make it fully compatible with Xiaomi’s cable.

Together the cable and power bank’s USB-A port supports a proprietary superset of USB Power Delivery and Quick Charge. Up to 100W by itself, or up to 65W when either of the USB-C ports is in use.

The cable functions like any other USB-C to USB-A cable away from ZMI’s power bank or its matching Xiaomi wall charger. Similarly, the USB-A port on ZMI’s power bank functions as a typical 18W Quick Charge 3.0 port with any other USB-C to USB-A cable.

Whether you use the cable or not is up to you. It is a proprietary setup from Xiaomi made for their own phone. My testing showed no indications it wouldn’t function as a third USB PD port, but neither did I do in-depth testing. If you normally shy away from non-standard protocols then you can just not use the cable. The USB-A port on the power bank reports as a typical Quick Charge 3.0 port with any standard USB-A cable.

Temperature Throttling

At or near 100W or more output the power bank will heat up and it could reach a point where it throttles the output to prevent an overheat situation. This is typical of high output power banks and should be considered good, as it means proper safety protocols are in place. Though it will feel more annoying than anything at the time.

If charging one laptop this likely won’t come up, as the laptop will reduce its power draw significantly after hitting 20% battery level. A high temperature is more likely when charging several devices for 100W or more total output.

If concerned about heat try to keep the power bank cool. Rest it on a non-insulating surface, such as a wooden table, and not on a bed or blanket. Keep it in range of air conditioning or a fan, blowing cool air over its surface. And always keep it out of direct sunlight. If the unit does throttle or shut down due to heat then disconnect the cables and allow everything to cool down. Such instances should be the exception more than the rule for most users.

PPS – Programmable Power Supply

Programmable power supply (PPS) protocol was added in USB Power Delivery 3.0. But not all PD 3.0 devices and chargers support it. In fact, it is uncommon now but will grow in use. It allows for small, step-wise changes in voltage and current. This reduces conversion loss during charging. The power transfer is more efficient and lithium batteries endure less heat.

Under PPS charging occurs in two phases. In the first phase, the current (amps) is constant, with a gradual increase in voltage. In the second phase, the voltage (now at a higher state) is constant, with a gradual decrease in current.

Devices that support PPS include:

• LG G7/G8 ThinQ
• LG V40/V50 ThinQ
• Razer Phone
• Samsung Galaxy S10 5G/A70
• Samsung Galaxy Note 10/10+
• Xiaomi Mi 8/9

Any device that supports Quick Charge 4+ will also support PPS. If your phone was released in 2018 or later you can check its specs to see if PPS is supported.

If your devices don’t support PPS this tech will not affect charge performance. And with this model, you’ll be future-proofed for a future PPS device.

Pass-Through Charging

Pass-through charging allows a portable charger to both charge itself and a connected device. Power goes from the portable charger to your device, while power from the wall outlet also goes into the portable charger’s own batteries. How it handles the split varies. And there are more inefficiencies than normal.

This portable charger supports pass-through charging under these connections:

• Input: USB-C (either), Output: USB-C, USB-A
• Each USB-C port supports its normal max output (100W or 45W)
• USB-A port supports normal Quick Charge with any cable and up to 65W USB PD with the Xiaomi cable

Pass-through charging is useful when you only have one USB wall charger. But it is not recommended to use this feature regularly. It puts more heat and stress on the portable charger. Which will affect its lifespan. It can also provide an inefficient charge to your device. Again, not great for its own battery’s lifespan. It is okay when traveling with limited wall outlets, but not something you should set up at home.

UPS

UPS (uninterrupted power supply) is a similar, but difficult and more uncommon feature. With regular pass-through charging power to your device can stop if power to the power bank stops. With UPS the power bank acts as backup power for your device in the event the main power fails.

During testing, I connected ZMI’s power bank to a USB-C PD wall charger. Then to a phone and monitored the phone’s power draw. When I turned off power to the wall charger there was no interrupt to power to the phone.

In the chart above I turned off power to the wall charger at the 30-second mark. As you can see, there was no change to voltage or current, indicating no power interruption to the phone. The power bank’s LED did change from single-digit blinking (indicating input power) to double-digit blinking (indicating output power).

This feature doesn’t matter much for charging your phone, laptop, or other devices with their own battery. But it is useful for a new Raspberry Pi 4, which uses USB-C PD for power without an internal battery. It would also work with a USB-C-powered Wi-Fi router or security camera.

Summary

The ZMI PowerPack No 20 will likely become my new go-to power bank when traveling with a laptop, replacing the ZMI PowerPack 20K Pro. I don’t need the full 100W output (yet), but the second USB-C port and no throttling of output are big upgrades.

• Fast charges iPhone 8/X/XR/XS/SE/11/12, Samsung Galaxy, and Google Pixel. As well as any other Android which supports USB PD or Quick Charge.
• PPS for supporting Android phones.
• Nintendo Switch fast charges in handheld mode as fast as any other option. And can power a docked Switch.
• The 45W output port supports small to mid-sized laptops, while the 100W port will support any USB-C-powered laptop.
• The two USB-C ports allow you to fast charge two devices of various combinations, with enough added capacity to back that up over a few hours.

The power bank is quite large for its capacity, a consequence of supporting so much simultaneous output. It is nearly the size of many 26,800mAh models while slightly less capacity. For me, the trade-off is worthwhile, as higher total output is in short supply. And the total weight is less when you consider this can replace carrying both a small power bank for your phone and a large power bank for your laptop.

You’ll want to use the included USB-C to USB-C cable for any 65-100W charge. The other USB-A to USB-C cable from Xiaomi also allows for up to 100W charging. But it isn’t using the open USB PD standard, rather its own superset of that standard. So anyone less comfortable with standard deviations may want to skip the USB-A to USB-C cable.

About ZMI

ZMI has U.S.-based support (web, email, phone) and an 18-month warranty. They were founded in the USA and were acquired by Xiaomi in 2021. They continue to operate as a standalone brand for niche charging accessories.

Bottom Line

The ZMI PowerPack No 20 offers high capacity and high output for one, two, or even three USB PD devices at once. Its 1-100 display, pass-through, and UPS functions are all icing on the cake.

Buy if you:

• Need a power bank capable of fast charging your 90-100W device, such as a MacBook Pro 16-inch.
• Have 2-3 devices you regularly want to fast charge together on the go.
• Want a single portable charging solution for your phone, laptop, and other devices.

Don’t buy if you:

• Only need a power bank for your phone, this model is overkill.
• Value size and weight over available charge time.