How Siri helps my iPhone live longer

Your iPhone battery will last longer if you don’t overcharge it and Siri can now help prevent that

It’s easy to get Siri to warn you when your phone is being overcharged

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My iPhone is old in phone years, a 6S+ that I bought six years ago (2015). By 2018, battery health was down to 85%. It wouldn’t even last a full day. In fact, Apple recommends you replace your battery if its health drops to 79%. Anyway, my phone was among those affected by Apple’s battery throttling scandal, and they replaced my battery at a discounted rate of ₹2000 ($27).

Charging to 100% shortens a battery’s life

What I learned from this experience was charging my phone to 100% is a bad idea as it causes the battery to overheat and reduces its life. Ideally, if you want your battery to last longer, you shouldn't charge it above 75%, and not let it discharge below 25%. Of course, the compromise is you get less capacity (uptime) than a 100% charged battery.

This charging practice is now widely accepted for lithium batteries, and 80% seems to be the magic number. Like electric car-maker, Tesla has programmed its car chargers to stop charging when it reaches an 80% charge, with the car’s dashboard simply showing the battery as fully charged at that point.

Anyway, I stopped charging my phone over 80% for the last three years, and the results are showing.

My iPhone is proof that undercharging works

Three years after replacing my phone’s battery, I can verify that avoiding overcharging does extend a battery’s life. My iPhone’s battery which I replaced in 2018 is still at 95% health.

Oddly enough, I do have a perfect baseline comparison for charging habits. You see my friend and I had purchased identical iPhone 6S+ models around the same time. I told him about Apple’s discounted battery replacement program, and he too replaced his battery a month after I replaced mine. However, he wasn’t too careful about his charging habits and often hit 100% charge. Whereas I stuck to a 20–80% charge range as far as possible. Three years later, his battery is at 85% as compared to my 95%.

Same phones, same age batteries, but mine (left) stayed within 40–80% charge range

The newer the phone, the better the performance

I must say my battery still does discharge quickly for processor-intensive tasks. Like if I shoot a video, the battery discharges at around 1% per minute. However, I don’t think the battery is at fault here. It’s just that the hardware of a six-year-old iPhone can’t keep up with the demands of the latest software (OS and apps) without the battery draining quickly.

However, if you have a newer iPhone and keep its battery in good health, your phone should give you noticeably better performance and longer life. My brother had an iPhone 11 Pro which he regularly charged to 100%. Its battery health dropped to 85% in just one year so he replaced it with an iPhone 12 Pro. I have set up the new iPhone to warn him to stop charging at 80%, and I’m sure its battery will last longer.

Avoiding overcharging is a chore

Unfortunately, unlike Tesla, Apple does not automatically turn off the phone charger at 80%. iPhones do have a software switch that allows the OS to control/stop charging. So theoretically, iPhone users should be able to decide to what percentage they wish to charge their phones. Or at the very least, iOS should warn them when their phones go past a certain preset battery charge level. But the feature hasn’t been provided to users as yet.

So we have to look for workarounds till this happens. What I do is every time I put my phone for charging, I estimate the time for my phone to reach 80% and ask Alexa to remind me to unplug it.

However, most people have too many other things happening in their lives to remember to unplug their iPhone when it reaches 80%. And few have the patience to calculate the time needed to reach 80% and then set timers.

Automation is the solution

I have been using an app called Battery Life to send me a notification when the battery reaches 80% while charging. On getting this notification, I unplug my charger. The problem is I often miss this notification. I don’t have this issue on my Android, as the Accubattery app I use has a distinctive alarm tone that is hard to miss.

Anyway, there’s actually a far more effective way to get this done. You use Apple’s automation app, Shortcuts. Now I have always been fascinated by Shortcuts because it lets you create small programs even if you don’t know a thing about coding. But I haven’t been dabbling in it for some time now and this new battery control shortcut went below my radar for a while. Basically, Shortcuts now gets Siri to speak up, and warn you when your phone battery level reaches a preset level. Here’s a quick video demo on how to set it. If you want more details, follow the explanatory, text version below the video.

Step-by-Step Demo

Open the ‘Shortcuts’ app, tap the ‘Automation’ button, and on the next page scroll down and select ‘Battery Level.’ (If this option is missing, then you need to update your Shortcuts app and iOS to the latest versions.)

Pull the slider from the default 50% to 80%, select ‘Rises above 80%’, then tap on ‘Next’ and in the search box, type ‘Speak.’

Tap on the Action, ‘Speak Text.’ Now type what you wish Siri says to you when the battery charge reaches the desired 80% level. This sentence needs to be a bit long as Siri will start speaking without warning, and you likely won’t catch the first couple of words that Siri babbles out. Like my initial suggestion was a two-word command like ‘Stop Charging’ but it didn’t even register in my hearing. You could try putting something funny, except funny becomes unfunny when you hear it every day. My observation was that a phone announcing its charge percentage, and then asking to be unplugged, did raise a few eyebrows, and that was good enough for me.

The default voices are a bit robotic. So I experimented around,

I settled for ‘Aaron’ in ‘English (United States)’ for clarity’s sake even though ‘Marie’ in ‘German’ was cooler. You can also experiment with the rate and pitch of the voice to suit your liking. (I did try recording a statement myself but it didn’t work. Should be possible though, but I need to spend time on it!)

Once you are done, play the voice a few times to ensure you are fine with it. Then exit the menu, by hitting the ‘Edit Automation’ on the top left. Then toggle off the ‘Ask before Running’ switch (to allow Siri to speak without any input from you).

That’s it. The next time you plug your charger into your phone, Siri will warn you to unplug it when your battery level reaches 80%. This will prevent your battery from overheating, keep it healthy, and give you better performance.

Good luck, and may your iPhone be blessed with a long life.