Amazon has two bestselling power banks for Prime Day, but this is the only one I'd buy

INIU B6 and Veektomx VT103 power banks on a blue background with the TechRadar Don't Miss deals logo
(Image credit: TechRadar)

Power banks have been hot sellers during this year's Prime Day sale, with two 10,000 mAh models jostling for top position on the Amazon bestsellers list. The showdown is between the INIU B6 and the Veektomx Mini (VT103), with both varying their discounts as they try to stay on top.

So which should you buy? I connected both up to a capacity tester and, as you can see in my best power banks roundup, the INIU B6 is the winner, passing with flying colours in my tests. Most importantly, it has the actual 10,000 mAh rating, and can output 85% of that after normal efficiency losses – an excellent result. For long-term testing, I also have an INIU B6 that has been in use for over a year and periodic checks show it hasn’t lost any capacity at all.

In the same tests, the Veektomx Mini outputted just 75% of the rated capacity – a well below average result. I also have a lightly used year-old Veektomx Mini, and it has degraded all the way down to 56% of the rated capacity. Sure, the Veektomx is slightly cheaper and slightly smaller, but it uses an under-specced battery that just can’t keep up.

So there you have it – the INIU B6 is the best affordable power bank you can currently buy. But maybe you are after a different capacity or type of power bank. To help out, I've included my top picks from this year's Amazon Prime Day deals below. 

INIU B6 22.5W 10,000 mAh Slim | AU$29.99AU$25.49

INIU B6 22.5W 10,000 mAh Slim | AU$29.99 AU$25.49 (save AU$4.50)

The B6 is the top-rated budget option in my best power banks buyers guide and aces my tests with a genuine capacity, 20W fast charging and a 3-year warranty. Ignore the higher RRP – the typical price is AU$29.99, making AU$25.49 a nice little discount. You can also score an extra 5% for a limited time, using the code N3TFIIMA.

Need a larger capacity? The INIU B5 is basically a bigger version of the B6 with a 20,000 mAh capacity. It's currently on sale for AU$39.99, which is equal to the lowest I've seen on Amazon. 

Anker 737 24,000 mAh 140W | AU$199AU$138

Anker 737 24,000 mAh 140W | AU$199 AU$138 (save AU$62)

This is one of the lowest prices I've seen for this premium power bank and gets some of the best results in testing for my best power banks guide. The Anker 737 has up to a 140W output, a 24,000 mAh capacity (86.4Wh, so flight safe) and an excellent 85% efficiency in my tests.

If you're after a more affordable option, the Anker 537 24,000mAh 65W power bank is on sale for a price equal to the lowest I've seen before. 

INIU B64 140W 27,000 mAh | AU$169.99 AU$95.99

INIU B64 140W 27,000 mAh | AU$169.99 AU$95.99 (save AU$74)

I'm currently in the process of testing this power bank, and initial impressions are this will find a way into my best power banks guide too. Better yet, AU$95.99 is one of the cheapest prices I've seen for it as well. The B64 has up to a massive 140W output for fast charging laptops, but is just as well suited to keeping a phone running for a week. The large capacity 27,000mAh (99.9Wh) power bank is flight safe, can charge 3 devices at once and is backed by a leading 3-year warranty.

The 65W / 20,000mAh B62 I recommend in my best power banks guide is also on sale for AU$55.99 (was AU$69.99). It's a great option for charging gaming devices such as a Steam Deck. 

Ugreen 145W 25,000mAh |AU$189.99AU$107.99

Ugreen 145W 25,000mAh | AU$189.99 AU$107.99 (save AU$82)

This deal offers an excellent 43% off (and an all-time-low price) on one of the top-rated options in my best power banks guide. It can charge at up to 145W, and has dual USB-C ports plus USB-A ,and is below the flight-safe limit for easy carry-on when travelling. Ugreen also has a number of other excellent power banks with big discounts – all currently in my buyers guide or undergoing testing with excellent early results. 

Ugreen 100W 20k power bank: AU$129.99 AU$77.99
Ugreen 30W 10k mAh power bank: AU$59.99 AU$39.99
Ugreen Magnetic Wireless 10k: AU$87.99 AU$56.54

Anker 533 10K 30W |AU$69.99AU$45.99

Anker 533 10K 30W | AU$69.99 AU$45.99 (save AU$24)

At the lowest price I've seen, the compact Anker 533 is a great option for fast charging your phone at up to 30W when on the go. The power bank also outputs up to 20V, so can charge a laptop if needed. The Anker 533 has dual USB-C ports (plus USB-A) and a great screen that tells you charge information and remaining capacity. I haven't tested the Anker 533 personally yet, but by all accounts it's a quality power bank. 

Vrurc T2055 20,000mAh 20W |AU$49.99AU$32.49

Vrurc T2055 20,000mAh 20W | AU$49.99 AU$32.49 (save AU$17.50)

This compact mid-sized power bank is a great option for fast charging your phone or other devices on the go. Especially when a smaller capacity power bank won't cut it. The T2055 is one of my top-rated options in my best power banks guide and is a great deal for AU$32.49.

Lindsay Handmer
Senior Writer – TechRadar Australia

Lindsay is an Australian tech journalist who loves nothing more than rigorous product testing and benchmarking. He is especially passionate about portable computing, doing deep dives into the USB-C specification or getting hands on with energy storage, from power banks to off grid systems. In his spare time Lindsay is usually found tinkering with an endless array of projects or exploring the many waterways around Sydney.