ZMI PowerPack 20000 High-Speed USB Charger Review: One Charger to Rule Them All

In this world full of technology that we all seemingly can’t live without, power is a premium. Our smartphones, tablets, laptops, and portable gaming devices all require rechargeable power sources, which means we unfortunately have to put them down to be plugged in and recharged at some point during the day. I can argue that may be just what humanity needs in this era of touchscreen devices, which have essentially become pacifiers for humans of all ages, but there’s also an argument to be made that the heavy daily use of these devices has also made many people and businesses much more productive and valuable. Either way, keeping these technological toys charged and ready for our constant tapping and swiping is paramount to heavy users who just can’t go a full day without having to plugin one or more of their portable supercomputers.

I can’t remember the last time I haven’t had to charge my smartphone throughout the day while driving from one destination to the next, or plugging it into the wall at night just so I can keep using it before going to bed. The more powerful iPhones, Android Phones, and tablets of any brand become, the harder it will be to keep their power sources topped up so you never have to be without them for an extended amount of time. This conundrum has spawned an entirely new market for people on the go who need the ability to keep their devices charged, but who also don’t have access to a physical outlet to do so. Portable batteries aren’t anything new, but even they have made some impressive leaps in recharging technology over the past few years.

One company that has gotten into this market is ZMI, and its latest High-Speed USB PowerPack device is equipped to handle a wide range of devices that a person may carry with them throughout their day. The ZMI PowerPack 20000 features 20,000mAh at 3.6V or 72Wh of battery cell power that can charge devices as large as laptops in relatively quick timeframes. It also supports USB-A, USB-C, and USB-Mini out of the box, so it literally should be able to charge most every available portable device that employs USB technology for charging purposes.

We were sent a review unit to test out, and it definitely didn’t disappoint. First off, it looks and feels like a high-end Apple device, so it immediately stood out to me thanks to its sleek design, which is about the same footprint size of an iPhone 8 Plus. It also is rather light at just under 15 ounces, so unlike other heavy-duty USB battery chargers, the PowerPack 2000 isn’t a bulky brick.

Looks clearly mean nothing when it comes to a product like this, so in terms of this charger’s abilities to keep your devices charged, it too excels in this era. It features three total USB ports with two of them being USB-A output ports, and the third being a two-way USB-C port. The A ports both support Quick Charge 3.0 technology, while the C port offers Power Delivery 2.0 tech. This basically means that this charger can juice up your gadgets quickly and efficiently, so expect to get a 20% charge on a iPhone X in about 20 minutes, with the first 15% of the charge coming in just over 10 minutes. That’s just using the USB-A ports, the USB-C port can cut those times down by a few additional minutes, so in terms of a quick charge, the PowerPack 20000 is very efficient. If you’re interested in how long it will take this battery pack to charge a completely dead iPhone, you should expect it to take less than two total hours to go from zero to one hundred.

I personally tested it with my iPhone X, iPad Pro, and Nintendo Switch. On just one full charge of the battery pack I was able to charge my iPhone X from 60% charge to 100% charge three different times, my iPad Pro from 70%-100% two different times, and my Switch from 65%-100% once, and the PowerPack 20000 still had one bar left on its own battery, so I probably could’ve squeezed another few percentages out of it for one of the three devices I tested with it. I didn’t have a laptop to test it with, but it will charge any laptop, including newer MacBooks, as long as they support charging through a USB-C port.

This particular charger also can be used as a USB data hub, so with a quick press of a button, you can use it to provide more open USB ports for your laptop or desktop. It can give you at least two additional open ports to plug other USB devices into such as a mouse or video game controller. It also will provide a light charge while in hub mode, so lower power devices can also charge while being used.

In terms of the PowerPack 20000’s own battery, it too can be recharged quickly if you pony up for a 45W USB charger. If you use this type of charger you can refresh the PowerPack’s batteries from 0% to full in just under four hours. If you have an 18w charger the recharge time goes up to just over 5.5 hours, or if you want to use an existing iPad charger you can expect the recharge process to take just under nine hours. Once it’s full, you should expect to get multiple quick charges out of it for your devices, so you shouldn’t have to worry about having to recharge its own batteries every day of the week.

If you’re in the market for a high-end looking superpowered USB charger, then look no further than ZMI’s PowerPack 20000. It supports a wide variety of devices that can be as large as a laptop. It just looks refined and doesn’t have a ton of weight to it, so it’s no hassle to lug around in your bag. Plus, it’s just a damn good all around USB charger thanks to its inclusion of USB-A and USB-C port technology. I’ll definitely be throwing it in my bag while I cover E3 next month for the site, because I know for a fact that I’ll have to tap into it after a long day hustling on the show floor, because there’s no way I’m missing out on my daily gameplay sessions with Star Wars: Galaxy of Heroes and Marvel Strike Force. A dead phone should never be my reality again with the ZMI PowerPack 20000 in my arsenal.

You can pick one up for yourself from Amazon for $69.95. The full specifications for this device can be found below.


Model No.: QB820
Battery Type: Lithium-ion cell
Cell Capacity: 20,000mAh at 3.6V or 72Wh
Operating Temperature: 32° to 113° F (0° to 45° C)
Input: USB-C 5-20V MAX 45W
Output: The combined power output over three ports is 45W MAX.

  • USB-C: 5-20V MAX 45W (15/3A) or 40W (20V/2A);
  • USB-A (×2): 5V/2.4A 9V/2A 12V/1.5A MAX 18W (two ports total). 

Dimensions: 6.31 × 3.22 × 0.83 in (160.4 × 81.8 × 21 mm)
Weight: 14.29 oz (405 g)
Color: Blue-tinged black


Review Summary

Build Quality - 9
Functionality - 9
Ease of Use - 10
Price - 7.5



In terms of portable USB battery chargers, you can't really go wrong with this sleek looking pack from ZMI.

Buy from Amazon


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Tags : Gadget Review
Matt Heywood

The author Matt Heywood

Matt Heywood is the founder and EIC of where he strives to make you a better geek, one post at a time! When he’s not scouring the Internet for interesting nuggets of awesomeness he can be found in his secret lair enjoying the latest and greatest video games, taking pictures of toys, or talking Star Wars on EB’s Star Wars Time podcast show.