iOS 18 is already among us… halfway there. We will have to wait for the introduction of the iPhone 16 to taste the latest version on the iPhone. Apple introduced many new features at WWDC 2024, but there was one thing it didn’t say was actually useful: a configurable maximum charging limit.

And that means…? Let’s start from the beginning. One of the most critical points of any device with a battery, not only a mobile phone but also a tablet, smart watch or electric car, is its lifespan. This is measured in cycles. The more cycles the battery offers us, the longer it will take for it to begin to deteriorate excessively, losing its capacity and therefore offering less autonomy.

What is a loop. A cycle is completed when we charge the battery to 100%. Charging from 0% to 100% is one cycle. Charging 20% ​​today, 40% tomorrow, and 40% the next is a cycle. It doesn’t matter how we do it. The cycle is completed when the total reaches 100. Batteries can last X number of cycles before they start losing performance. A ten-cycle battery will offer greater autonomy than a 600- or 1000-cycle battery. This is called “battery health”.

If your mobile phone is old, you have never changed its battery and you noticed that it is slow and has much less autonomy, that’s why. Cycles increase, the battery degrades, autonomy deteriorates, and the device adjusts performance to maintain a power/autonomy relationship that allows us not to have to charge the phone every two hours. There are many other factors, but this is one of the most important.

USB-C port on iPhone 15 Pro Max | Image: Xataka

20/80 rule. How can we optimize the device’s charging to extend its lifespan? With good charging habits. There are two that are highly recommended. First, avoid fast charging when we don’t need it. Second, keep the battery charged between 20% and 80%.

Scientific evidence shows that the areas between 0-20% and 80-100% are the most critical areas. Charging at these intervals increases battery degradation, requires more power, and produces more heat. In short, charging the phone when it is about to shut down or leaving it on charge for longer than necessary may be to our detriment.

Problem. This requires some intervention on our part. If we want to keep our mobile phone charged between 20% and 80%, we need to worry about plugging and unplugging it in time. The first one is easy but the second one is another story. Charging your phone before it drops below 20% is simple, but if we have a habit of charging our phone at night, the reality is that no one will wake up at four in the morning and unplug the phone at 80%. .

It is now possible to set an upload limit in iOS 18 settings | Image: Xataka

Solution. If we enable optimized charging on iPhones, the battery will charge up to 80% and the mobile phone will not charge up to 100% until it thinks we will wake up. Now with iOS 18 we can go even further: We can limit the maximum charge to 80%. Thus, when we put the phone on charge, it will automatically stop when it reaches 80%. This is something phones from Samsung, Huawei, OPPO, Realme, and Sony can already do, and now it’s reaching Apple’s phones as well.

It actually arrived relatively recently with iOS 17, but with iOS 18 this system goes a little further, as we will see later. In any case, by combining the low battery notification (skipping when we reach 20 percent) with the 80 percent charge limit and slow charging, we can adopt healthier charging habits. This will not prevent the battery from failing. It will do this because it is still a consumable, but at a lower rate.

Survive with 60%. This is the counterpart of this habit: it limits us to spending the day with 60% battery; This is something that not all mobile phones can afford, even less if we use it intensively (brightness at maximum, GPS working, heavy games, recording a video…). Ultimately, it’s a matter of weighing both and making a decision based on our context. Or, in cases where we know mobile usage will be intense, act proactively and disable the limit.

In this sense, Apple’s approach is interesting; because it allows us to set the limit at 80%, but it can also make jumps from 5% to 100%. So if we see that we’re a little tight at 80 percent, we can adjust the limit to 90 percent. The idea here is to reduce the time the phone spends in these two critical areas we mentioned earlier.

Pictures | Xataka

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