Charge the cell phone battery it seems like one of the most banal operations of the day. Yet, almost no one does it right. And no, it’s not a question of being picky: incorrect charging habits actually reduce the life of the battery, up to halving it. With non-removable built-in batteries now dominating the smartphone market, this often means having to replace the entire phone sooner than expected — with a significant impact on your wallet and the environment.
The good news? A few simple precautions are enough to make a huge difference. But first we need to stop believing in some hard-to-die myths.
Let’s dispel the myth of the “memory effect”
Many of us still have the rule of old nickel-cadmium batteries in our heads: discharge everything, then recharge everything. It was the so-called “memory effect”a real problem for the technology of a few decades ago. Today, however, smartphones use lithium-ion (or lithium-polymer) batteries, which work in a completely different way. For these batteries, total discharge is not maintenance: it is unnecessary and harmful stress.
Taking your battery to zero — or worse, letting your phone turn off on its own — and then recharging it to 100% is one of the worst treatments we can give it. Each complete charging cycle (from 0 to 100%) consumes the chemical capacity of the cells more rapidly, reducing autonomy over time.
The mistake you shouldn’t make again
But there is another equally widespread error, perhaps even more common: Leave your phone charging overnightor in any case well over 100%. This practice — known as “trickle charging” — keeps the battery under constant voltage for hours, accelerating the deterioration of the internal components. It’s not so much getting to 100% that’s the problem, it’s getting stuck there for a long time.
The latest research in the field of battery health confirms what engineers at Apple, Samsung and other manufacturers have known for a long time: the comfort zone for a lithium ion battery is between 20% and 80% charge. Some studies even suggest staying between 30% and 90% to maximize longevity. Keeping the battery constantly at maximum or minimum generates thermal and electrochemical stress which, over time, translates into reduced capacity and increasingly poor autonomy.
The rule of thumb? Charge your phone when it drops to around 20-25% and unplug it when it reaches 80-90%. Yes, that means don’t charge it at night — or at least don’t do it without adequate protection.
The smart functions that (maybe) you already have and don’t use
The good news is that smartphone manufacturers have started to take the problem seriously. Many recent devices — iPhones with iOS 13 and up, several Android models from Samsung, Google Pixel, OnePlus, and others — have optimized or intelligent charging which learn your habits and automatically limit charging to 80% during the night, only completing it shortly before you wake up.
It’s worth going into your smartphone’s settings and checking if this option is available: it’s usually found under “Battery” or “Battery care”. Activating it is one of the simplest — and most effective — gestures to extend the life of your device.
Another habit to adopt: avoid charging your phone in very hot environments or while you use it intensively (gaming, video streaming). Heat is the number one enemy of lithium batteries, and charging already generates heat: adding the two factors significantly accelerates degradation.
Because doing so is also a green choice
There is also an environmental aspect that should not be overlooked. Prolonging the life of the battery — and therefore of the smartphone — means producing less electronic waste, one of the fastest growing waste streams in the world. Every year, millions of electronic devices are disposed of before they are needed, resulting in a huge waste of resources and a significant impact on the environment. Taking care of your battery is, in a small way, also an act of conscious consumption.
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