Are you one of those who leave their smartphone charged overnight? Rest assured if the answer is yes, you are probably not alone. However, the real question here is what are the consequences? Is leaving the device connected overnight to a power source harmful to the life of your battery? Here are the answers to the questions you are asking yourself.
As Cambridge University professor David MacKay explained to us in 2015, whose conclusions from the latest study were shared by the American site Techradar, the simple fact of leaving your charger plugged into an AC outlet consumes energy, even if your smartphone is not charging. A consumption which nevertheless remains negligible since in terms of cost, in one year, this corresponds to the electricity consumption necessary for a hot bath.
Why not plug in your smartphone all night
According to a previous study by the Lawrence Berkeley National laboratory, leaving a charger connected alone to an electrical outlet is equivalent to an average power of 0.26 watts. When the phone is charged, it goes to 3.68 watts. Finally, when it is 100% charged, but still connected to the mains, this figure drops to 2.24 Watt. Generally, the annual cost corresponding to the energy spent to recharge our smartphones is equivalent to 5.30 dollars or 4.55 euros for an average household. A cost which therefore remains negligible on an individual scale, but not for the environment.
The manufacturers of smartphones were inspired by portable PCs to set up a security to avoid any heating of the battery which could lead to its explosion. When the smartphone battery is fully charged, the charge is stopped and then resumed. This leads to a redundant cycle which will inevitably make you consume a little more electricity. It is therefore strongly advised to charge the smartphone that is turned off overnight, if there are no other options.
Of course, the question that burns our lips is this: is it dangerous for the battery to leave your phone on charge overnight? Although the impacts remain minimal, the study specifies that in the long term, leaving a lithium-ion battery 100% charged permanently or almost reduces its lifespan. Thus, according to experts, it is best to unplug it for short periods during charging.