BMX SolidSafe Air 5K Review: The thinnest Qi2 magnetic power bank we’ve tested

At a glance

Expert rating

Benefits

• Super slim
• Impressive battery power

Our Verdict

The SolidSafe Air is by far the thinnest 5K Qi2 semi-solid-state power bank you can buy. Indeed, in our experience, this is the thinnest magnetic wireless power bank. And it impressed us during our iPhone charging tests.

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I still have external batteries that I have trouble holding in one hand. Such items hide in the back of a cupboard just waiting for the end of days rather than a long train journey or city vacation.

Batteries have been getting smaller and smaller for years, but recent advances have shrunk phone power banks to the size of a shirt pocket.

Solid electrolytes replace flammable liquid electrolytes with more stable and efficient materials that enable smaller, more compact and safer batteries. Although we have not tested any fully solid-state external batteries, we have observed semi-solid cells in which flammable liquid is reduced to a fraction of that found in standard lithium-ion batteries.

It’s not just about size: these batteries are safer and should last much longer with a greater number of cycles before the battery degrades.

BMX

Size matters: How thin is it compared to other Qi2 power banks?

But size matters when you carry the power bank in your pocket or backpack.

BMX, not the little bike ridden by kids and hipsters, but a company called Better Mobile

The SolidSafe Air 5K doesn’t stray far from the typical length and width of today’s magnetic wireless power banks (4.1 x 2.8 inches / 103 x 70 mm), but when it comes to depth (or height, whichever way you look at it), it’s truly tiny at just 0.27 inches (6.8 mm).

In comparison, the iPhone Air is only slightly thinner, at 5.6mm, with a battery capacity of 3,149mAh (12.4Wh).

While we haven’t tested every wireless power bank model out there, we’re proud to vet all of our most trusted power brands, including Anker, Ugreen, Belkin, EcoFlow, Baseus, Kuxiu, ESR, Statik and more.

The margin may be down, but the SolidSafe Air 5K actually lives up to BMX’s claims.

The closest we have measured in terms of slimness are:

By all accounts, the SolidSafe Air is the thinnest 5K magnetic wireless power bank we’ve tested.

Simon Jarry

Weight matters too

And its weight? When it’s on you or in the bag you’re carrying, weight is as important as size; if not more. The SolidSafe Air weighs 4.1 oz (116 g); For comparison, the iPhone Air weighs 165g.

Let’s compare this to our other slim power banks mentioned above.

• BMX SolidSafe Air 5K: 4.1 ounces (116 g)
• Anker Nano 5K MagGo Slim: 4.3 ounces (122g)
• Vonmählen Evergreen Mag 5000mAh: 4.34oz (123g)
• PhoneSuit Elite Mag Slim 5K: 3.88 ounces (110g)
• Baseus PicoGo ultra-thin 5K: 3.77 ounces (107g)
• Kuxiu S2 5K (also in semi-solid state): 6.14 oz (174 g)
• Infinacore M3 Mini 5K: 3.88 ounces (110g)

The SolidSafe Air is therefore not the lightest external battery we have tested. That honor goes to the Baseus PicoGo Ultra-Slim.

However, we don’t think 0.32 oz or 9 g will be perceptible by anything other than a precision scale.

BMX

Design: Does the slim design affect battery life or charging speed?

The SolidSafe Air is so thin that the magnetic coil must be slightly elevated from the otherwise flat surface of the power bank.

Looking at the distance between the USB-C charging port and the sides, I think it will be almost impossible to get slimmer, but fear not, someone will do it.

BMX

It is available in a choice of three colors: Titanium Gold, Titanium Black and Titanium Silver. Add a Sky Blue model and the iPhone Air models would all match. BMX has certainly tried to create a power bank that is slim enough for iPhone Air users.

The battery indicator is a standard set of four LEDs that tell you how much power is left in the power bank’s battery. One of the thinnest power banks we’ve reviewed is the PhoneSuit Elite Mag Slim 5Kand this one has a digital percentage display, which is much more accurate, but such a display on a 5K power bank is, and to its credit, the SolidSafe Air’s LEDs are brighter than most.

The SolidSafe Air is reinforced with titanium to make it more resistant to shocks. This, combined with the safer semi-solid electrolytes, should make the power bank inherently safer than most power banks.

Semi-solid cell technology reducing flammable liquid content improves thermal stability and reduces the risk of fire compared to conventional lithium-ion batteries. This should also mean that the SolidSafe Air can be charged, discharged, and recharged many more times than a traditional lithium-ion power bank.

Performance also matters

The 5,000 mAh (milliamp-hour) battery is rated at 18.5 Wh (watt-hours). This is the perfect spot for a power bank that is lightweight and slim, but still has enough capacity to provide decent charging for the iPhone. Remember that the battery capacity of the iPhone Air is 3,149 mAh (12.4 Wh). The iPhone 17 Pro Max’s 5,088 mAh (20 Wh) battery is the closest. Find out the battery capacity of your iPhone in our long list.

We test power banks by reducing an iPhone 16 Pro to 0% and seeing what percentage the power bank can take of the phone’s battery. In this test, the BMX SolidSafe Air 5K achieved an impressive score of 89%, one of the highest of any magnetic wireless power bank we’ve had at Macworld Labs.

Simon Jarry

The SolidSafe Air uses Qi2 magnetic charging technology and can therefore deliver up to 15W of wireless power.

Some larger 10K power banks, such as the Kuxiu K1, Baseus PicoGo 25W 10K, Ugreen MagFlow, and Sharge Icemag 3, use the new Qi2.2 technology that can handle 25W for compatible iPhones (iPhone 16 and later). 25W should charge an iPhone (16 or later) from 0 to 50% in about half an hour, while 15W takes about 45 minutes. We’re still waiting for a 5K power bank as fast as 25W.

Use the charging port with a cable (USB-C to USB-C for iPhone 15 and later, USB-C to Lightning for older iPhones) to gain 20W of power a little faster. A nice feature is simultaneous wired (using a cable into the power bank’s charging port) and wireless charging. Using this method, you get 10W wired plus 12W wireless for 22W of power, which isn’t that far off from the 25W that Qi2.2 would have provided.

The power bank itself charges at up to 15W, which is quite slow compared to others that have input speeds between 18-30W. If you charge overnight or aren’t in a rush, it shouldn’t matter. A full charge of the external battery should take approximately 2 hours.

Price

The SolidSafe Air 5K Solid-State Qi2 Power Bank is available on the BMX website for $59.99, with sales on Amazon beginning in late March.

For alternatives, check out our reviews of the best magnetic wireless power banks.

Should You Buy the Qi2 BMX SolidSafe Air 5K Solid State Power Bank

The titanium SolidSafe Air is ultra-thin and can slip into a shirt pocket without worrying about seams. You can charge your iPhone (12 and later) wirelessly at 15W or 22W when using both wired and wireless outputs, which is fast. There are power banks that charge faster and power banks with smarter battery displays, but the BMX SolidSafe Air is by far the thinnest 5K Qi2 semi-solid-state power bank you can buy – indeed, in our experience, it’s the thinnest magnetic wireless power bank.