ZMI USB PD Backup Battery

Last updated date: April 12, 2019

Review Melt Score

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We looked at the top 1 Portable Chargers and dug through the reviews from 6 of the most popular review sites including New York Times Wirecutter, iLounge, Switch Chargers, Charger Harbor, Entertainment Buddha and more. Through this analysis, we've determined the best Portable Charger you should buy.

Overall Take

In our analysis of 59 expert reviews, the ZMI ZMI USB PD Backup Battery placed 3rd when we looked at the top 9 products in the category. For the full ranking, see below.

Editor's Note March 31, 2019:
Checkout The Best Portable Charger for a detailed review of all the top portable chargers.

Expert Summarized Score
6 expert reviews
User Summarized Score
81 user reviews
Our Favorite Video Reviews
What experts liked
A unique and useful perk is that it can function as a USB hub when connected to a computer’s USB-C port, letting you plug in flash drives, cameras, or even printers to the battery’s USB-A ports.
- New York Times Wirecutter
Although the 20,000 mAh capacity of PowerPack 20000 is impressive, it’s certainly not the first portable battery to pack in that capacity. However, PowerPack 20000 distinguishes itself from many others by offering support for all of the standard fast charge protocols — USB PD 2.0, QC 3.0, BC 1.2 — in both directions.
- iLounge
June 28, 2018 | Full review
The PowerPack 20000 includes a USB-C power cable that handled charging the MacBook and recharging the internal battery pack.
- Macworld
February 9, 2018 | Full review
The ZMI QB820 is a great, large capacity USB-C PD power bank for the Nintendo Switch. It’ll charge the Switch at the fastest possible rate in handheld mode, equal to any wall charger.
- Switch Chargers
What makes using this power bank even better is that it actually goes beyond charging with its two USB-A ports and that’s because once you connect the USB-C port to a laptop, you can use it as a USB Hub.
- Charger Harbor
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.
- Entertainment Buddha
May 11, 2018 | Full review
What experts didn't like
There’s no Lightning cable here, so you’ll need to supply your own if you want to use it with your iPhone or iPad.
- iLounge
June 28, 2018 | Full review
The battery doesn’t come with an adapter, which is a mark against it not on cost, but because it can be tricky to find a good adapter that matches the PowerPack 20000’s wattage.
- Macworld
February 9, 2018 | Full review
My only gripe is the size and weight, but it is no bigger or heavier than any other power bank of similar capacity.
- Switch Chargers
It's quite large and heavy and not really meant for holding and charging your devices.
- Charger Harbor

From The Manufacturer

Since 2014, Zimi Corporation has cumulatively sold over 80 million portable chargers/battery packs worldwide, including our PowerPack line of fast-charging battery packs. The PowerPack 20000 offers more power storage and faster charging speeds than any PowerPack ever. No matter where you go, the PowerPack 20000 will make sure your phone or laptop stays charged. With the PowerPack 20000, you no longer have to constantly search for an open power outlet. You no longer have to be stuck in an awkward position while trying to charge and use your phone at the same time. You can lie comfortably in bed and watch hours of movies on your laptop. Or you can explore the world and always have enough power to stay connected to your friends and family. Whether you are an avid gamer or a business person always on the go, the PowerPack 20000 will ensure you stay charged wherever you go, whenever. Note: When traveling by plane, FAA regulations require you to store your portable charger in your carry-on luggage, NOT checked-in luggage. So there's this growing trend in laptops that only offer one port...we can solve that problem. With the PowerPack 20000, you get 2 devices in 1. Not only a portable charger, the PowerPack 20000 also has a USB Hub mode (USB 2.0 compliant) that delivers data transfer over its USB ports. Need to connect a mouse to your laptop? Plug it into the PowerPack 20000. Need to access an external flash drive? Plug it in. Need to connect a gaming controller? Plug it in. In addition, the USB Hub mode is perfect for powering your smaller devices that will require a smaller charging current. These may include smart watches, Bluetooth headphones, fitness trackers, and other wearables. With these features, you can create a portable office (or gaming center), so you can get some serious work done wherever you go.

Overall Product Rankings

1. Anker PowerCore+ Portable Charger
Overall Score: 8.8
Expert Reviews: 5
2. Jackery Supercharge Portable Charger
Overall Score: 8.6
Expert Reviews: 3
3. ZMI USB PD Backup Battery
Overall Score: 8.5
Expert Reviews: 6
4. Jackery Portable Charger Bar
Overall Score: 8.5
Expert Reviews: 6
5. RAVPower 10000mAh Portable Charger
Overall Score: 8.4
Expert Reviews: 3
6. AUKEY Power Delivery Power Bank
Overall Score: 8.3
Expert Reviews: 4
7. Anker PowerCore+ Mini Portable Charger
Overall Score: 8.3
Expert Reviews: 11
8. Intocircuit Portable External Charger
Overall Score: 8.0
Expert Reviews: 9
9. RAVPower Portable Charger
Overall Score: 7.3
Expert Reviews: 3

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