Smartphone battery: good habits to adopt for more durability

You are more than a thousand to have answered our little questionnaire on the use of your smartphone battery. It is time for us to unveil the results and comment on them in the company of Olivier Simon, “in charge” in particular of the score battery at DxOMark.

Everything for autonomy!

According to our survey, you are a huge majority — 92%! — to prefer good battery life to fast charging of your smartphone. A more than clear-cut opinion which, let’s face it, surprises us a little. Indeed, a few years ago, batteries had a ridiculous autonomy and fast charging was just wishful thinking. Today, the situation has clearly changed. The autonomy of a smartphone is generally more than correct and the fast charge very effective in saving time. We thought (wrongly therefore) that fast charging would be a more important criterion for you. It may suffer from a bad reputation, that of weakening the health of accumulators.

Beyond the power of the chargers, it is the voltage that must be taken into account. “The higher the voltage of a charger, the more complicated it is for the battery to manage.underlines Olivier Simon. Today, manufacturers try to apply the highest amperage with the lowest voltage, and thus increase the durability of batteries”. For the moment, no study comes to corroborate these statements.

DxOMark is currently working on the subject and the case will be followed up in 2022. However, to benefit from efficient fast charging, it is advisable to use the charger offered by the manufacturer, because beyond the power delivered, the chargers communicate with smartphones to optimize charging. Communication that can be complicated, if not impossible, with a “classic” charger. A smartphone that accepts fast charging up to 66 W can thus very well limit the power to 10 W with the latter. “It is often for security reasonsexplains Olivier Simon. The faster the charge, the more the phone will ask to know what it is using for charging. Sometimes, it will have to be able to recognize the charger, but also the cable to be sure to pass a high amperage without taking any risks.”

The 80-20 rule for charging

On how to recharge your batteries, the results are more in line with our expectations. Thus, you are 60% to recharge your mobile as soon as the battery is less than 20%, which is a good reflex to limit wear. Indeed, as Olivier Simon explains, batteries degrade more quickly when the voltage is very high (charge level above 90%) or very low (below 20%). It is therefore preferable to multiply short charging cycles rather than letting your smartphone discharge completely.

Conversely, leaving your mobile plugged into a power outlet when it is at 100% battery will gradually degrade your battery. In question, of “small surges applied by the charger to the battery, which is already at its maximum voltage to maintain the level”, says Olivier Simon. These overvoltages affect the quality of the battery, whether you charge your smartphone in wired mode or by induction. Also be aware that it is better to charge a cold battery and, on the contrary, to use your smartphone at the right temperature.

Optimization of operating systems

However, the iOS and Android operating systems manage search and battery usage better and better. A few years ago, Sony took into account the morning alarm to adapt the recharge to 100% a few minutes before. A strategy widely adopted by other manufacturers. Google has greatly improved its operating system, especially since version 9 Pie.

In the past, the various manufacturers offered techniques to kill apps in the background in order to limit consumption, but this era is now over. We now know that relaunching a service ultimately requires a lot of energy. With the machine learning embedded which responds to the sweet name of Auto Awesome Battery, Android is now able to analyze the use made of applications to optimize their use. “No need to kill WhatsApp in the background if it is used every 5 min”, details our interlocutor. Another example, Android is able to know, by interrogating the gyroscopes of the mobile, if there has been a physical displacement or not and to“prohibit in the latter case a request for geolocation costly in energy made by a running application”.

Which is more effective, iOS or Android?

In this race for autonomy, who is the best? “On consumption in use, Apple and its iPhones are ahead with six devices in our Top 10”, points out Olivier Simon. Apple masters both the hardware design and the operating system, so it’s easier for this computer giant to optimize battery usage. “With a smaller battery, Apple does as well as an Android device with a higher battery capacity”adds the DxOMark expert.

As often, the marketing figures displayed by brands do not make much sense. Thus, indicating the capacity of a battery is limited information that only gives a vague overview of the autonomy that can be expected from a smartphone. “It’s like indicating the volume of a car’s tank without taking into account the consumption characteristics”, laughs Olivier Simon. Our autonomy tests therefore still have a bright future ahead of them.

Some tips to maintain your smartphone battery

As we have seen, iOS and Android optimize the use and recharging of the battery as well as possible. The fact remains that it is possible to increase its lifespan by respecting a few basic rules.

• Preferably recharge the battery when it indicates between 20 and 80%. Do not wait for it to drop below and recharging beyond 80% damages your battery.
• Unplug your smartphone when the gauge indicates 100%, or even before.
• Avoid using your smartphone when it is charging. Playing games, using a GPS app, making calls or leaving the terminal in the sun increases its temperature while recharging does the same, which damages it.
• If you don’t need Bluetooth, wifi or geolocation, turn them off, because the device constantly and automatically checks for updates and launches constant energy-consuming requests to do so.
• For the same reasons, prefer a wifi connection to 4G/5G if possible.
• Use the original charger provided/sold with your smartphone or recommended by the manufacturer (designed to optimize speed and optimal charging power for the model).
• Consider using Android’s dark mode if you have a smartphone with an Oled screen.
• Use auto-brightness to adapt the screen backlight to the mood.

Finally, to save your battery, the first instinct is quite logically to activate the energy saving mode on your smartphone. The smartphone will then limit access to data from apps that are not in the foreground and will pause the GPS when the device screen is off.

→ Google tips to optimize your battery life
→ The score battery by DxOMark