MagSafe batteries are getting really slim

Just in time for the iPhone 17 Air

Since Apple introduced MagSafe to the iPhone 12 five years ago, it’s become one of my favourite things about the entire iPhone line. The long-awaited switch to USB-C with the iPhone 15 garnered much more attention, but it’s MagSafe that makes a bigger difference to the iPhone experience, at least for me — because it means I almost never plug my phone in.

From the docking stand on my desk to the charger I use in cars, Apple’s magnetic wireless charging system is now a full-on ecosystem that’s hard to leave once you’re used to it. The new Qi2 standard is said to be based on and compatible with MagSafe, but more than two years after its launch, not a single Android phone has the magnets built in.

I’ve been thinking of that discrepancy lately because of the 2025 trend for thinner phones, like the Samsung Galaxy S25 Edge and the rumoured iPhone 17 “Air”. While I don’t have much nostalgia for the days when Apple and others were relentlessly pursuing thinness with every new release, I believe there’s now a market for these devices as performance-per-watt becomes less of a constraint. There’s no reason why design-forward phones shouldn’t be able to last a full day for most people.

That said, anyone who buys one of them should probably also be thinking about accessorising it with a mobile battery. MagSafe is theoretically a great solution for this, because you can attach a wireless charging battery and continue to use your phone without having to muddle with cables. Those batteries tend to be pretty chunky, granted, so they don’t feel all that natural in use. But I recently found out about some incredibly thin options that really change the experience.

What I picked up myself is the “MagOn Ultra Slim 5000” from a Kyoto-based company called Matech. It cost me 4,890 yen, or about $33. Matech claims it’s the world’s slimmest mobile battery with a capacity of 5,000mAh.

How slim? At 6.9mm, it’s significantly thinner than my 8.3mm-thick iPhone 16 Pro Max. You can feel it’s there when attached, of course, but it doesn’t get in the way of using the phone at all. 6.9mm is actually the same thickness as the iPhone 6, which remains the thinnest iPhone to date — at least until the 17 Air comes along. You could easily slip this battery into a jeans pocket and forget about it.

The absolute thinnest MagSafe battery I could find comes from Australian company Snap, whose PowerPack Slim 2 is just 5.95mm thick. You take a big hit in capacity, though, at 3,000mAh.

The Matech’s capacity of 5,000mAh is a little higher than the iPhone 16 Pro Max and the same as what most flagship Android phones carried until the recent wave of silicon-carbon batteries. That doesn’t mean you’ll get a full charge, given the inherent inefficiencies of wireless charging. But I found this Matech battery to deliver what I’d want from it on most days — basically, if your iPhone drops below the fatal 20% mark and starts recommending you switch to Low Power Mode, a full charge will get you back up past 80%.

That’s the recommended range for battery charging anyway, both in terms of lifespan and speed. Most phones switch from constant current to constant voltage when charging above 80%, which dramatically slows speed but avoids overheating or other damage to the battery. Any mobile battery — and particularly a wireless one — is going to be much less efficient once your phone gets that full.

So, a battery like the MagOn Ultra Slim 5000 sits right in the sweet spot. It’s convenient to carry, but it can cover the full range that you’d actually want to charge on the go.

The one downside is speed. This battery only charges at 7.5W, so it takes its time to get you there. I attached it to my iPhone 16 Pro Max at 20% and it took a full hour to get the phone half full. After a further 30 minutes, the phone was at 70%, and the Matech battery was nearly depleted after two full hours of charging to 81%. It finally gave up the ghost at 82%, 126 minutes after I started charging.

I didn’t actively use the phone while charging, nor did I turn on Low Power Mode. You’d probably get better results if you did the latter, and you definitely wouldn’t get to 82% if you were playing Fortnite at full screen brightness the whole time.

That’s basically what I’d expect from any 7.5W wireless battery, but it does mean this isn’t the best option for emergencies. For that, I prefer Anker’s 5,000mAh Nano Power Bank, which has a flip-out USB-C plug and charges at 22.5W. While it’s not as thin or convenient to use the phone with, it’s still very pocketable and useful when I need a faster charge.

But man, who knew MagSafe batteries could be like this. The closest similar review I could find in a major outlet was this on the Torras MiniMag Power Bank from ZDNet’s Kayla Solino — who opens the review by saying “Testing MagSafe battery packs is one of the larger parts of my job”, so I trust her — and that’s significantly thicker at 8mm while matching the same 5,000mAh and 7.5W specs. Even at those dimensions, Solino said the Torras “knocks my socks off” and agrees that it makes a huge difference to usability for a MagSafe battery to be that thin.

Meanwhile, Anker — usually my go-to brand for this sort of thing — just launched its own take on the concept called the Nano MagGo Power Bank, which is 8.6mm thick. It does charge at 15W wirelessly, though, which could tip the needle for some people weighing it against other options.

The Matech battery alongside a previous 5,000mAh MagSafe battery from Anker

Apple discontinued its own MagSafe battery a while back, but it’s planning to release a battery case alongside the iPhone 17 Air, according to The Information. As a no-case person, that doesn’t sound like a great solution — especially for a phone where its pure physical form is the whole appeal.

But I think the existence of these slimline MagSafe batteries changes the buying equation for the iPhone 17 Air. It will clearly have worse battery life than the 17 Pro Max, and it won’t be the best choice for power users. If an accessory as tiny as this Matech battery can guarantee that you’d make it through the day, though, wouldn’t you be more tempted?