Macworld

At a glance

Expert's Rating

Pros

  • Super slim
  • Impressive battery power
  • Color choices

Our Verdict

The SolidSafe Air is the equal-slimmest semi-solid-state 5K Qi2 power bank you can buy—indeed, if you want the slimmest magnetic wireless power bank this is your first stop. And it impressed us in our iPhone recharging tests, being just 1% off the current champion.

Price When Reviewed

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Best Pricing Today

Best Prices Today: BMX SolidSafe Air 5K Solid-State Qi2 Power Bank

Retailer Price BMX $59.99 View Deal Price comparison from over 24,000 stores worldwide

I still own power banks that I struggle to grip in one hand. Such items lurk in the bottom of a cupboard awaiting only the end of days rather than a long train journey or city break vacation.

Batteries have been getting smaller for years, but recent advances have slimmed phone power banks to shirt-pocket size.

Solid-state electrolytes are replacing flammable liquid electrolytes with more stable, efficient materials that allow for smaller, more compact, and safer battery designs. While we haven’t tested any fully solid-state power banks, we have been seeing semi-solid-state cells where flammable liquid is reduced to a fraction of that found in standard lithium-ion batteries.

It’s not all about size—these batteries are safer and should last significantly 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 does matter when you’re carrying the power bank in your pocket or backpack.

BMX, not the little trick bicycle ridden by kids and hipsters but a company called Better Mobile Xperience, has just released a new magnetic wireless power bank that it claims is the “world’s thinnest” 5,000mAh Qi2 power bank.

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

In comparison, the iPhone Air is only slightly thinner at 5.6mm, with a 3149mAh (12.4Wh) battery capacity.

While we haven’t tested every single wireless power bank model that exists, we pride ourselves in checking out all those from our most trusted power brands, including Anker, Ugreen, Belkin, EcoFlow, Baseus, Kuxiu, ESR, Zens, Statik and more.

The margin might be coming down in size, but the SolidSafe Air 5K does indeed live up to BMX’s claim, although the Baseus Picogo Air Magnetic Power Bank (AM71) matches it on slimness if not quite on performance (82% vs 89%).

The closest we have measured in terms of slimness are:

  • BMX SolidSafe Air 5K: 6.8mm
  • Baseus Picogo Air (AM71): 6.8mm
  • Anker Nano 5K MagGo Slim: 8.6mm
  • Vonmählen Evergreen Mag 5000mAh: 8.6mm
  • PhoneSuit Elite Mag Slim 5K: 8.9mm
  • Baseus PicoGo Ultra-Slim 5K: 8.9mm
  • Kuxiu S2 5K (also semi-solid state): 10mm
  • Infinacore M3 Mini 5K: 10.6mm

Clearly, the SolidSafe Air is the thinnest 5K magnetic wireless power bank that we have tested, alongside the non-solid-state Baseus AM71.

Simon Jary

Weight matters too

What about its weight? When it’s on your person or in the bag you are carrying, weight is as important as size; if not more. The SolidSafe Air weighs 4.1oz (116g); to compare, the iPhone Air weighs 165g.

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

  • BMX SolidSafe Air 5K: 4.1oz (116g)
  • Baseus Picogo Air (AM71): 3.7oz (105g)
  • Anker Nano 5K MagGo Slim: 4.3oz (122g)
  • Vonmählen Evergreen Mag 5000mAh: 4.34oz (123g)
  • PhoneSuit Elite Mag Slim 5K: 3.88oz (110g)
  • Baseus PicoGo Ultra-Slim 5K: 3.77oz (107g)
  • Kuxiu S2 5K (also semi-solid state): 6.14oz (174g)
  • Infinacore M3 Mini 5K: 3.88oz (110g)

The SolidSafe Air is therefore not the lightest power bank we’ve tested. That honor goes to the Baseus PicoGo Air.

However, we don’t think 0.4oz or 11g is going to be noticeable by anything other than a set of precision scales.

BMX

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

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

Looking at the distance between the USB-C charging port and the sides makes me think it will be nearly impossible to get any thinner—but, fear not, someone will.

Gold, Black, and Silver were the first SolidSafe Air 5K portable chargers released.

BMX

It’s now available in a choice of five colors: Gold, Black, Silver, Burgundy, and Glacier. That covers all the equally thin iPhone Air and now iPhone 18 Pro models with the latest Glacier and Burgundy colors.

BMX has now added Burgundy and Glacier colors to match more iPhones, including the iPhone 18 Pro models.

BMX

The battery indicator is the standard set of four LEDs to let you know 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 5K, and this boasts a digital percentage display, which is far more accurate, but such display on a 5K power bank is are, and to its credit, the SolidSafe Air’s LEDs are brighter than most.

The SolidSafe Air is reinforced with titanium to make it more durable against impact. That combined with the safer semi-solid electrolytes should make the power bank inherently safer than most power banks.

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

Performance also matters

The 5000mAh (milliamp hour) battery is rated at 18.5Wh (watt hours). This is the sweet spot for a power bank that is lightweight and slim but still has enough capacity to offer a decent iPhone recharge. Remember the iPhone Air’s battery capacity is 3149mAh (12.4Wh). The closer match is the iPhone 17 Pro Max’s 5088mAh (20Wh) battery. Find out your iPhone’s battery capacity in our long list.

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

Simon Jary

The SolidSafe Air employs the Qi2 magnetic charging technology, so can supply up to 15W of power wirelessly.

Some larger 10K power banks—such as the Kuxiu K1, Baseus PicoGo 25W 10K, Ugreen MagFlow and Sharge Icemag 3—use the newer Qi2.2 tech that can handle 25W for compatible iPhones (iPhone 16 and later). 25W should charge an iPhone (16 or later) from 0-50% in around half an hour, while 15W takes about 45 minutes. We are still waiting for a 5K power bank that is 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 a little faster 20W of power. A neat function is simultaneous wired (using a cable in the power bank’s charging port) and wireless charging. Via this method you get 10W wired plus 12W wireless for 22W power—not so far off the 25W that Qi2.2 would have supplied.

The power bank itself is charged at up to 15W, which is quite slow in comparison to others that have input speeds of between 18-30W. if charging overnight or not in a hurry, this shouldn’t matter. A full recharge of the power bank should take around 2 hours.

Price

The SolidSafe Air 5K Solid-State Qi2 Power Bank is available on the BMX website for $59.99, with Amazon sales starting at the end of March.

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

Should you buy the BMX SolidSafe Air 5K Solid-State Qi2 Power Bank

The titanium SolidSafe Air is wafer-thin and can slip into a shirt pocket without worrying the stitching. 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 recharge themselves faster, and power banks with smarter battery displays, but the BMX SolidSafe Air is the slimmest semi-solid-state 5K Qi2 power bank you can buy—indeed, in our experience, it’s both one of the slimmest and lightest magnetic wireless power banks on the market.