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Can I Charge My Apple Watch With My iPhone? (Read This First!)

The Apple Watch battery should last 18 hours on an overnight charge. But what if you forget to charge it overnight? Can you use your iPhone to give your watch battery a boost?

Your Apple Watch can’t charge from your iPhone or iPad. The lightning port of your iPhone is incompatible with the Apple Watch, and there is too much voltage variance between the devices. You can’t use your iPhone’s charger cable either, and the Apple Watch doesn’t support Qi wireless charging.

Many consider this a severe oversight on Apple’s part, and it would have been great if you could charge your Apple Watch with your iPhone. But there’s an actual good reason why Apple won’t allow it, at least not yet. Let’s see how the Apple Watch’s battery should be charged and why charging it in any other way may not be the best of ideas.

Why You Can’t Charge Your Apple Watch With Your iPhone

Interestingly, the technology that can allow you to charge your Apple Watch with your iPhone already exists, but Apple has not yet utilized it. Some Android phones already support reverse wireless charging, which means that you can use your phone’s wireless charger to charge other wireless-charging compatible devices. So why not the Apple Watch? There are a few reasons.

Apple’s Lightning Port Doesn’t Support Reverse Charging

In theory, it would be great if you could simply plug a lightning cable into your iPhone and link it with your Apple Watch’s wireless charger. Unfortunately, it’s not that simple. The lightning port wasn’t designed to output a strong enough current to charge another device.

According to schematics, the iPhone’s lightning socket can provide approximately 2.5 volts maximum, whereas the Apple Watch (like most other devices) requires at least 5 volts to charge. The lightning port can provide enough power for things like external storage, but that’s about it. Apple never intended for it to be used as a power socket.

To stop people from accidentally using it in an unauthorized (and unsafe) way, Apple placed a controller chip inside the iPhone to prevent any unauthorized devices from connecting to the lightning port. So charging your Apple Watch through the iPhone’s lightning port isn’t possible.

The Apple Watch Isn’t Compatible With Qi Wireless Charging

The iPhone uses a wireless charging technology called Qi. It has become a standard that’s used by most of the well-known smartphone manufacturers. As mentioned, some of these manufacturers have managed to create reverse-charging using Qi technology, meaning users can charge other devices wirelessly from their phones.

The Apple Watch is not compatible with Qi and uses an entirely different wireless charging technology. That means you can’t use your iPhone’s wireless charging capabilities to charge your Apple Watch, even if you could manage to activate reverse-charging.

But why did Apple design it this way?

Unfortunately, Apple remains quiet about the topic, so we don’t have any direct answers from the tech giant. However, some experts agree that it has to do with the heat generated by Qi charging. Heat is harmful to modern lithium-ion batteries. Smartphones are robust enough to handle the heat, but the tiny battery contained within the Apple Watch would be too sensitive to this heat.

That reason would make sense since heat won’t only reduce the Apple Watch’s battery life, but it has risks for the user, too. Remember the exploding smartphone batteries of a few years back? That was partially caused by heat generated while the phones were charging, so imagine carrying a tiny bomb around your wrist.

Yes, chances of this happening are slim, but the decades have made Apple experts at avoiding anything that could cause their users harm (not to mention potential lawsuits).

What About The “Alternative Chargers For Apple Watch” Rumors?

Many companies have attempted to develop different, “better” ways to charge the Apple Watch. Some have been shut down, and others turned out to be scams; but for the most part, there is no real alternative to genuine Apple chargers. Some of the attempted options were:

The Reserve Strap

Possibly the attempt that came closest to being successful was called Reserve Strap. It was a watch strap that connected to the Apple Watch’s six-pin diagnostics port, hidden where one of the straps connects to the body of the watch. People found that they could charge their watches around 7% faster using this port than through the regular charging cable.

Apple eventually shut this operation down, again due to claims of potential harm to the users. The company said there’s a possibility of people getting burns on their wrists from this, which makes sense if you look at how hot a device can become when you’re charging it.

Eventually, Apple registered a patent for the charging wrist strap, but we will have to wait and see if they’re ever planning to do something about it or only registered it to keep other people from doing it.

Togvu’s Batfree Power Strap

A company called Togvu made a massive impact on social media several years ago, promising a strap that could charge an Apple Watch. The strap claimed to have two lithium-ion batteries that could give the Apple Watch an additional 27 hours of power without you ever removing your watch. A Kickstarter campaign was launched, and people bought into the brilliant concept.

Unfortunately, this project never went anywhere. Togvu was reported to the FBI, and backers are still fighting both Togvu and Kickstarter to get their refunds, which is unlikely ever to happen. It seems the Batfree power strap might have been nothing but a scam, as such things are happening almost daily on Kickstarter. 

How Should You Charge An Apple Watch?

The best way to charge any Apple device is always any way that Apple provides. If you use Apple’s charging technology in the way that Apple recommends, you can guarantee the longest possible battery life and a valid warranty in case something goes wrong. Apple offers only one way to charge an Apple Watch, which is through an approved Apple Watch wireless charging dock.

Modern Apple Watches come with a USB-C charging cable. The cable has a USB-C port on one end and a magnetic charging dock on the other. 

You can plug the USB-C connector into any compatible USB-C port, including the one found on modern Apple charging bricks or the ones that are built into Macs and other computers. They should all be able to provide enough power to charge your Apple Watch.

But you don’t have to use Apple chargers. Many other brands manufacture Apple-approved wireless chargers for the Apple Watch, including some that are so impressive that they can charge your Apple Watch, iPhone, and AirPods simultaneously, taking up only one power socket.

Will It Ever Be Possible To Charge Apple Watch With iPhone?

The technology exists, and it has been done before. Samsung, for example, allows reverse-wireless charging, and the Samsung Gear supports Qi. Apple is known for waiting until the technology matures a bit before adopting it, so it is entirely possible that this is also the case with charging an Apple Watch with an iPhone. 

There seems to be interest or thought going into alternative ways to charge the Apple Watch from Apple’s side since Apple’s lawyers have been busy registering patents over the years since the watch launched. There is definitely a chance that we could see it happening over the next few years.

However, it’s also possible it won’t since Apple isn’t rushed to push any new technology. Apple won’t take the risk unless it is 100% sure that the system will work and work well.


As things are at the moment, you can’t charge your Apple Watch with your iPhone. The possibility is there on the horizon but not fully realized quite yet. For the time being, ensure that you charge your Apple Watch in the recommended way, and perhaps invest in a second charger so you always have a backup option handy if your charger should get damaged or stolen, especially if you use it daily.