Charging your smartphone at night: Myth or reality for battery conservation?

We're all used to recharging our smartphones overnight. Although it only takes a few hours to fully recharge, our precious devices are often left plugged in for eight hours or more! However, the technology behind our phones, the lithium-ion battery, has one drawback: it is damaged when subjected to excessive voltage. What's more, overcharging can cause the battery to overheat, as we saw with the infamous Galaxy Note 7s catching fire.

To avoid this kind of disaster, most manufacturers have introduced systems that automatically cut off the power supply when the charge is complete. However, even when the phone is in standby mode, it undergoes a slight discharge. When the battery reaches a certain threshold, recharging starts again, increasing the level to 100 %, and is repeated several times during the night. These incessant "mini-recharges" wear out the battery prematurely and cause the phone to heat up.

But that's not all. The phone is not the only culprit when it comes to wasting energy. When the battery is full and the charger remains plugged in, it continues to consume electricity. According to Berkeley Lab, a charger consumes an average of 3.68 watts when charging and 2.24 watts when plugged in, even when the battery is full. An unnecessary waste of energy.

So how can you extend the life of your battery?

It's recommended that you keep the charge between 30 % and 80 %, in other words, that you don't let the battery run down completely or charge it fully. A small change in your charging habits could well extend the life of your precious digital companion.