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Review : ZMI 20,000 mAh USB Battery Pack/USB Hub with Power Delivery – My new favorite USB Battery Bank


I have a problem, I love USB battery packs and my collection keeps growing, it is getting so bad that I am running out of space in my backpack. Many of my USB battery packs have a similar set of features, the ZMI 20,000 mAh Battery Pack is very different as it not only puts out enough power to charge my PixelBook at full speed but it pulls double duty by acting as a USB 2.0 hub at the same time.

For full disclosure, I purchased the ZMI 20,000 mAh USB Battery Pack out of my own personal funds and have owned it since July of 2018. I specifically purchased it on Amazon Prime Day as part of a sale.

The ZMI 20,000 USB Battery Pack has a basic selection of ports including 2xUSB A ports and 1xUSB Type C Port. The Type C Port acts as both an input and a high powered output. The package includes a short Type C to Type C cable, a USB A to MicroUSB/Type C Combo cable and a travel pouch. It does not include a charger in the box so it is strongly advised to pick up a USB Power Delivery Charger if you do not have one to ensure that you are charging the ZMI USB Battery Pack at full speed. A full charge takes about 2.5 hours on my USB Power Delivery charger. There are indicator lights on the side of the unit to allow you to see the battery level, sadly no LCD display.

What sets the ZMI USB Battery Pack apart from the thousands of other options out there is that it not only puts out enough power to run my Pixelbook while also acting as a USB 2.0 hub. This means that you not only can connect your phone to one of the USB A ports to charge but you can also connect a mouse, keyboard, portable hard drive and more to the USB ports on the ZMI Battery Pack and it will just work as if you were using a USB Type C Hub. As an added bonus, the ZMI will continue to charge your device while acting as a hub. This is perfect as many modern laptops are starting to remove USB ports in favor of Type C ports. This Battery Pack/USB hub will work with any modern operating system including MacOS, Windows, Linux, ChromeOS and even with Android Phones/Tablets with a Type C port. The only downside of the ZMI is that it is limited to USB 2.0 speeds.

The ZMI has a very small footprint that makes it slightly bigger than the Samsung Galaxy Note 8. It is perfect for travelers and frequent flyers as it is72 Wh which means it easily falls under the 100 Wh maximum limit imposed by commercial airlines. You must travel with this battery in your carry on luggage but are free to use it aboard your flight when it is safe to use electronic devices. You will easily be able to fit this battery in a pocket or backpack for easy access.

This battery is very powerful and will easily provide several charges to mobile phones, tablets, USB Type C laptops and even the Nintendo Switch. It will provide about 2 charges of my Pixelbook with enough juice left over to charge my Note 8. You can also expect around 4 full charges of the Nintendo Switch if you are into gaming.

My only two things I wish I could change about the ZMI 20,000 mAh battery is that I wish it had a SD Card/Micro SD card reader on it and I would have loved to see a 4 port option (with 2 USB 3.0 ports). This would make it perfect for photographers and those who work on the road. You can of course plug an additional USB Hub with a card reader into one of the USB ports but I would have loved to see this integrated into one package and not limited to USB 2.0 speeds.

The ZMI 20,000 USB Battery Pack is selling for around $70.00 on Amazon.