THE MORNING LIST
Time is not forgiving with the batteries of our smartphones. From the first or second year, their autonomy begins to decrease. After three to five years, their stamina drops to the point that some owners have them changed. The cost of replacement varies between 40 and 100 euros.
Abused, a battery degrades faster than if it is pampered. However, it is difficult to know by how much. “Scientific studies carried out in the laboratory provide little information on the aging of batteries in real conditions. Smartphone brands choose battery technologies that don’t look exactly alike, and tune them differently.”explains Olivier Simon, director of batteries at DXOmark, a French laboratory for measuring the performance of electronic devices.
How to delay the aging of a battery? You can set a reasonable goal by focusing on the tips that, among those that follow, seem the least restrictive to apply. Or try to apply all these recipes, at the cost of constant attention.
Avoid high temperatures
Modern smartphones are equipped with lithium-ion batteries, designed to be used between around 10°C and 30°C. When permanently exposed to higher temperatures, they degrade rapidly. It is better to avoid placing a smartphone in direct sunlight, especially when it is charging. The worst case scenario for overheating combines sun, charging and heavy use – “when using your smartphone as a GPS over a long distance, for example”, warns Olivier Simon. Or when you play with your smartphone while recharging it.
The temperature of our skin being high, especially in summer, it is better to avoid carrying a smartphone in tight pants or in the inside pocket of a coat. Conversely, in the heart of winter, when temperatures fall below 0°C, it is advisable to wear your smartphone close to your body to slow down battery wear.
Avoid full discharges
There is no need to discharge a lithium-ion battery to 0% from time to time, contrary to the practice that prevailed with certain older generation batteries. It is even now not recommended: this type of battery degrades more quickly when it drops below 20% charge, a “danger zone” to be avoided as much as possible. The chemistry of a current smartphone battery perfectly supports frequent charges, it can be recharged often. However, it is not recommended to recharge it as soon as the opportunity arises, because its comfort zone is between 30% and 80% charge. It is also better to wait until the gauge of your smartphone drops to 25 or 30% before plugging it in.
Avoid overnight charges
Batteries wear out faster above 80% capacity. It is therefore recommended to avoid charging them overnight: “They would spend too much time at 100% and it would damage them prematurely”, explains Olivier Simon. Especially since some brands are not very cautious:
“While testing the charging of mobiles from different brands, we found that several models send regular surges when the battery is at 100%, to keep it fully charged. It’s bad enough for her. »
As a precaution, it is better to apply the same rule regardless of the brand: “Charge your battery in the morning, when you shower, for example”advises Olivier Simon.
If you want to give more attention and energy to this problem, look at the battery settings of your mobile: some models, at Samsung, Apple, Sony and Google, provide smart tuning. At night, to avoid staying at 100% too long, they monitor the user-programmed alarm, and block the load at 80% for several hours, then push it to 100% only at the last moment. In most cases, it is up to you to enable this feature.
If you’re willing to put a lot of effort into protecting your battery, you can go one step further: make sure the gauge never goes above 80%. A painful solution, because it reduces the autonomy of the smartphone on a daily basis and forces you to monitor the recharge like fuel on the fire. On Android, you can get assistance of an app which emits an alert when the load passes the fateful threshold of 80%. On iOS, one can use the Shortcuts app for this.
Some users allow themselves to carry the load up to the 85% threshold, because the manufacturers all take a margin of safety. “The 100% you see on the screen never matches their full battery capacity. Some more conservative brands set this 100% further from the maximum battery capacity than others”explains Olivier Simon.
The Fairphone 4 is one of the very few smartphone models whose battery can be easily changed.
Allow fast charging?
Some smartphones from Chinese manufacturers are able to recharge in less than thirty minutes: should we worry about the health of their battery? ” Probably not “Judge Oliver Simon. “Their fast charging processes seem to me to have been well studied. The key is cooling, and some brands have invested in technologies that dissipate heat particularly efficiently: graphene sheets, for example.”or two compartment batteries that charge separately.
With most manufacturers, fast charging would therefore have little effect on the longevity of the batteries. A manager of Xiaomi, a brand that invests a lot in accelerating charging, let the American media know The Verge that a slow-charged battery was only marginally more durable than a battery that was consistently fast-charged.
Store with gauge at 50%
Before storing a smartphone for several weeks, you must discharge its battery to the level that wears it the least: around 50%. If you want to store it for a few months, you can slow down its aging by storing it in a dry place where the temperature never exceeds 25°C, such as a cellar. But even if the smartphone is turned off, its battery will drain over time, at a very slow rate: Apple recommends applying a recharge every six months to raise the gauge to 50%. If you are aiming for storage of several years, the cold of a refrigerator, a few degrees above 0°C, further slow down battery wear. In this case, store the smartphone in an airtight container and add a few grains of rice which will absorb the humidity.