At night, before going to sleep, we sometimes spend some time on our smartphone. We can sometimes use it by leaving it connected to the mains. The risk then becomes important when we doze off and leave the phone charging all night. This can indeed lead to risks of burns or electrification. We tell you more in this article.
Since the human body is a conductor of electricity, it is easily exposed to accidents caused by electrical currents. Therefore, plugs and electronic devices, such as cell phones, are a source of considerable risk that must be taken into account.
Why shouldn’t you leave your phone on charge all night?
Risks of electrification
Keeping your phone charged overnight can lead to electric shock and burns, especially when the phone is charged using a USB charger or a generic charger.
A generic charger is a cheap charger that does not meet safety standards. While they have the advantage of being less expensive than a branded charger, their safety and quality are in question.
Research published in Annals of Emergency Medicine reported the case of a 19-year-old patient who received second-degree burns around her neck from her charger. The young woman’s phone was not charging, but her charger was plugged into an outlet and the wire remained under her pillow. According to doctors, the end of the charger touched the girl’s necklace and that’s what let the electric current through.
A study cited in the report evaluated the electrical resistance of 400 generic chargers marketed as iPhones. This test examines the ability of these chargers to more or less let electric current through. Only 1% of these chargers passed this test. This means that leaving a generic charger plugged in all night leads to a risk of electrical leakage that leads to electrification.
Note that electrification is different from electrocution. Electrification results in serious injury and damage but not death, while electrocution is fatal. In this case, the electric current passes through the heart, causing a cardiac arrest.
According to Doctissimo, in addition to burns, electrocution can cause other serious problems such as respiratory tract damage, breathing difficulties or heart rhythm disorders called arrhythmias.
These accidents are not specific to phones. But any device using a USB charger or a generic charger can expose its owner to the risk of electrification. Whether it’s tablets, laptops, or even e-books.
For her part, Carissa Bunke, a pediatrician at the University of Michigan Children’s Hospital, also advises not to sleep with the phone on charge and not to leave the charger plugged into an electrical outlet when not connected to the phone.
As a precautionary measure, avoid keeping your phone on charge unattended. Also, keep it away from flammable objects, such as bedding. That said, avoid charging your phone on your bed and never place the charger under your pillow. The heat generated by the charger is trapped and can ignite your pillow or bed.
Impact on battery life
Phone batteries have a limited lifespan. However, certain habits can shorten it, such as keeping the smartphone charged all night.
This generation’s phones are equipped with a lithium-ion battery. This type of battery has the advantage of recharging quickly, but does not support a high voltage that may damage it. And so letting your phone exceed the threshold of 100% impacts the autonomy of the battery. The phones of this generation are equipped with a system that stops the current when the charge is full. However, the battery life is still affected. Indeed, since the phone undergoes a slight discharge even when not in use, the charge will be triggered each time the battery drops below a certain level, in order to reach a 100% charge again.
To increase the life of your battery, Dominik Schulte, managing director of the German battery technology consultancy, recommends keeping the charge of your phone between 30% and 50%. That is, don’t let the battery discharge completely and don’t charge the battery to more than 100%, in order to preserve its performance and not change the battery anytime soon.