Testing Whether Fast Charging Kills Smartphone Batteries, And Other Myths

November 10, 2025 by Maya Posch 27 Comments

Calendar aging of NMC Li-ion cells at 50 ℃ at various SoCs. (Credit: Wiljan Vermeer, IEEE, 2021)

With batteries being such an integral part of smartphones, it’s little wonder that extending the period between charging and battery replacement has led to many theories and outright myths about what may affect the lifespan of these lithium-ion batteries. To bust some of them, [HTX Studio] over on YouTube has spent the past two years torturing both themselves and a myriad of both iOS and Android phones to tease out some real-life data.

After a few false starts with smaller experiments, they settled on an experimental setup involving 40 phones to investigate two claims: first, whether fast charging is worse than slow charging, and second, whether limiting charging to 80% of a battery’s capacity will increase its lifespan. This latter group effectively uses only 50% of the capacity, by discharging down to 30% before recharging. A single control phone was left alone without forced charge-discharge cycles.

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Animated Widgets On Apple Devices Via A Neat Backdoor

May 17, 2025 by Lewin Day 7 Comments

If you’ve ever looked at widgets on your iPhone, you’ve probably noticed they’re largely static, save for a few first-party apps. By and large, third party developers are not supposed to be able to animate them. However, [Bryce Bostwick] found a workaround.

You might be confused as to the idea of animated widgets, but it’s quite simple. For example, think of a clock app with a widget in which the hands always display the current time, or a calendar app with an icon that shows the current date. Apple’s own apps have long been able to do this, but the functionality has mostly been locked out for third parties.

One way to get around this limitation is by using a timer feature baked into the widget functionality. The timer tool is one of the few ways that third-party apps are allowed to do animation. By running a timer with a custom font, you can display various graphical elements instead of numbers counting down to create a hacky animation that updates every second.

However, there are even more advanced techniques that can get you faster, smoother animations. [Bryce] breaks down the private techniques used to rotate the clock hands on Apple’s own widget, and how to use those tools for your own purposes. It takes some sneaky Xcode tricks and a bit of math to make it fully flexible for doing arbitrary animations, but it works surprisingly well.

Will this backdoor last ? Well, Apple is always updating and changing iOS and its associated software, so don’t expect it to work forever.

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Emulating IPhone On QEMU

April 6, 2025 by Al Williams 4 Comments

[Georges Gagnerot] has been trying to emulate iOS and run iPhone software in a virtual environment. There were a few choices, and qemu-t8030 had a number of interesting features that you can check out in his post.

The project requires a patched QEMU, and [Georges] did some basic jailbreaking techniques. The real problem, of course, was not having the Apple Silicon GPU. Older versions of iOS let you select software rendering, but that option is gone on newer versions. However, it was possible to patch the phone to still use software rendering. There are still apps that directly use Metal or OpenGL that won’t run, but that’s another problem.

There is a plan to explore forwarding GPU calls to a real device. However, that seems difficult so it will have to wait for now.

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Tech In Plain Sight: Magsafe, And How To Roll Your Own

February 25, 2025 by Al Williams 8 Comments

Apple likes magnets. They started out with magnetic laptop chargers and then graduated to a system that magnetically holds the phone, charges it, and can facilitate communication between the phone and a charger or other device. Even if you are like me and have no Apple devices, you can retrofit other phones to use Magsafe accessories. In fact, with a little work, you can build your own devices. Regardless, the technology is a clever and simple hack, and we are just a little sorry we didn’t think of it.

Terms

Using a magnet to attach a phone isn’t a new idea. But, historically, the phone had either a metal back or an adhesive metal plate attached that would stick to the magnet. This wouldn’t necessarily help with charging, but was perfectly fine for holding the device. The problem is, it is hard to wirelessly charge the phone through the metal.

Magsafe can do several different things. Obviously, it can attach the phone magnetically. However, since it is a ring shape, you can still have a charging coil in the middle of the ring. Better still, the Magsafe system will align the phone and charger with a satisfying click when you put them together.

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IPhone 15 Gets Dual SIM Through FPC Patch

September 30, 2024 by Arya Voronova 10 Comments

It can often feel like modern devices are less hackable than their thicker and far less integrated predecessors, but perhaps it’s just that our techniques need to catch up. Here’s an outstanding hack that adds a dual SIM slot to a US-sold eSIM iPhone 15/15 Pro, while preserving its exclusive mmwave module. No doubt, making use of the boardview files and schematics, it shows us that smartphone modding isn’t dead — it could be that we need to acknowledge the new tools we now have at our disposal.

When different hardware features are region-locked, sometimes you want to get the best of both worlds. This mod lets you go the entire length seamlessly, no bodges. It uses a lovely looking flexible printed circuit (FPC) patch board to tap into a debug header with SIM slot signals, and provides a customized Li-ion pouch cell with a cutout for the SIM slot. There’s just the small matter of using a CNC mill to make a cutout in the case where the SIM slot will go, and you’ll need to cut a buried trace to disable the eSIM module. Hey, we mentioned our skills needed to catch up, right? From there, it appears that iOS recognizes the new two SIM slots seamlessly.

The video is impressive and absolutely worth a watch if modding is your passion, and if you have a suitable CNC and a soldering iron, you can likely install this mod for yourself. Of course, you lose some things, like waterproofing, the eSIM feature, and your warranty. However, nothing could detract from this being a fully functional modkit for a modern-day phone, an inspiration for us all. Now, perhaps one of us can take a look at building a mod helping us do parts transplants between phones, parts pairing be damned.

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The FPC adapter shown soldered between the BGA chip and the phone's mainboard, with the phone shown to have successfully booted, displaying an unlock prompt on the screen

IPhone 6S NVMe Chip Tapped Using A Flexible PCB

March 3, 2024 by Arya Voronova 3 Comments

Psst! Hey kid! Want to reverse-engineer some iPhones? Well, did you know that modern iPhones use PCIe, and specifically, NVMe for their storage chips? And if so, have you ever wondered about sniffing those communications? Wonder no more, as this research team shows us how they tapped them with a flexible printed circuit (FPC) BGA interposer on an iPhone 6S, the first iPhone to use NVMe-based storage.

The research was done by [Mohamed Amine Khelif], [Jordane Lorandel], and [Olivier Romain], and it shows us all the nitty-gritty of getting at the NVMe chip — provided you’re comfortable with BGA soldering and perhaps got an X-ray machine handy to check for mistakes. As research progressed, they’ve successfully removed the memory chip dealing with underfill and BGA soldering nuances, and added an 1:1 interposer FR4 board for the first test, that proved to be successful. Then, they made an FPC interposer that also taps into the signal and data pins, soldered the flash chip on top of it, successfully booted the iPhone 6S, and scoped the data lines for us to see.

This is looking like the beginnings of a fun platform for iOS or iPhone hardware reverse-engineering, and we’re waiting for further results with bated breath! This team of researchers in particular is prolific, having already been poking at things like MITM attacks on I2C and PCIe, as well as IoT device and smartphone security research. We haven’t seen any Eagle CAD files for the interposers published, but thankfully, most of the know-how is about the soldering technique, and the paper describes plenty. Want to learn more about these chips? We’ve covered a different hacker taking a stab at reusing them before. Or perhaps, would you like to know NVMe in more depth? If so, we’ve got just the article for you.

We thank [FedX] for sharing this with us on the Hackaday Discord server!

apple airtag being opened to remove the sounder

Apple AirTag: Antitheft Or Antistalking?

February 24, 2024 by Dave Rowntree 37 Comments

Occasionally, the extra features added to a product can negate some of the reasons you wanted to buy the thing in the first place. Take, for example, Apple’s AirTag — billed as an affordable way to link your physical stuff to your phone. If some light-fingered ne’er-do-well wanders by and half-inches your gear, you get notified. The thing is, the AirTag also has an anti-stalking measure, which after a while, notifies nearby iPhones, should the tag move but not be near your iPhone!

In a recent video, [David Manning] explains that this feature is great for preventing the device from being used to track people. But it also means that if said thief happens to own an iPhone, they will be notified of the nearby tag, and can find it and disable it. So in the end, it’s a bit less useful as an anti-theft measure!

The solution is to pop the back off the tag and yank out the little sounder module from the rear plastic. You lose the ability to locate the tag audibly, but you gain a little more chance of returning your stolen goods. Apple could easily remove this feature with a firmware update, but it’s a matter of picking your poison: antistalking or antitheft?

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