Make your iPhone switch off its charger by itself

Indian Ink
Published in
4 min readOct 31, 2022


Let Apple and Amazon create magic

When Siri spoke to Alexa

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Charging a phone to 100% reduces its battery’s life as they tend to overheat when charged above 80%. This is why Samsung has a feature that lets us limit battery charging to 85%.

My Samsung can be set to stop charging at 85%

I wish my iPhone 12 Mini had this option. But it seems Apple didn’t get my memo. However, that doesn’t mean you can’t do this on an iPhone. Actually, you can go a step further and get your iPhone to physically switch off the charger.

Watch what happens when my Mini’s battery goes above 80%.

A short video version of this post

I’m sure others have done this. But I’m clueless about coding. So figuring it out on my own was both magical and hilarious. I know machines usually communicate far more complex messages with each other, but that’s in code language. However, this message by my phone is meant for humans so it’s speaking in audible English. That’s what makes it funny. Like, AI casually happening on the corner side-table of my bedroom.

Anyway, to make this happen, you need two gadgets: a smart speaker and a smart plug. If you already have this, then you are good to go. Assuming your smart speaker is an Echo triggered by the wake word, ‘Alexa,’ and your smart plug is called ‘plug,’ then if you say, “Alexa, turn off the plug,” your Echo should switch off your plug.

What you do next is connect your phone’s charger to the smart plug. Then download the shortcuts app on your iPhone and set it to give a voice notification when your battery touches 80%.

The hack is to make that notification trigger your smart speaker to switch off the smart plug. In short, when your phone battery level reaches 80%, the voice notification from your iPhone should say loud and clear, “Alexa, turn off the plug.”

When gadgets speak to each other in English

If you don’t know how to set up the Shortcuts app to give audio notifications linked to battery levels on your iPhone, just follow the instructions in the video linked below. Or read here my earlier post on the same subject which has detailed instructions.

Using the Shortcuts app to make Siri tell you when your battery reaches a preset level like 80%

Anyway, here’s what I did to get Siri and Alexa to play nice with each other. I changed the wake word for my smart speaker from ‘Alexa’ to ‘Computer,’ and renamed my smart plug as ‘charger.’ So my voice command to turn off my plug would be ‘Computer, turn off the charger.’ You can stick with the defaults of ‘Alexa’ and ‘Plug’ though.

A couple of caveats.

As anyone who has used voice commands knows, outside sounds can interfere with a smart speaker’s ability to pick up that command from my phone. Barking dogs, passing bikes, my own voice… My workaround is to repeat the command on my phone at 85%. Maybe once more at 90% if you want to play safe.

Secondly, the volume button on my phone can sometimes be accidentally triggered to reduce the volume, and the smart speaker may not pick up the command. This can be maddeningly hard to troubleshoot. But the fix is simple. Go back to the page in the Shortcuts app where the text is entered, hit the play button at the bottom of the screen, and manually increase volume using the ‘volume up’ button while the phone is reading out the command.

Thirdly, I found that my Echo speaker was likelier to miss the wake word, ‘Alexa’ than ‘Computer’. Maybe three syllables is easier than two syllables for it to pick up. That’s why I used ‘Computer’ as its wake word.

Finally, the cost. Most folks have smart speakers lying around at home. So the additional expense is just the cost of the smart plug. Just wait for the next Amazon Sale, and pick up the Echo Dot for inside ₹2000, and Amazon Smart Plug for ₹999. Other brands should work and may cost less, but I haven’t tried them and can't vouch for them.

Anyway, I now plug my phone in when I go to bed, like before battery overheating became a thing. And I sleep soundly knowing my phone will turn off the power source when its battery level touches 80%.

That’s it. Happy AI-ing.