Whether we’re talking about phones, laptops or wireless headphones, our lives are punctuated by the recharging of multiple devices. But what really happens when you leave a charger plugged in all the time, even if there’s no device at the end of the line? Glen Farivar, a specialist in power electronics at the University of Melbourne, has looked into the matter.
A charger, even an inactive one, consumes electricity continuously. This phenomenon, known as “vampire power”, refers to the energy absorbed by devices on standby. If we consider a single charger, the impact seems minimal. But multiplied by the number of appliances in a household, the amount of energy wasted over the course of a year is not negligible.
To understand this invisible expense, we need to look inside the charger. Its main role is to convert alternating current (AC) from the electrical network into direct current (DC) adapted to the appliance’s battery. This conversion requires several components: a transformer, conversion circuits, filters and regulation systems.
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Even without a connected device, some circuits remain active to ensure safety and power management, which explains the residual power consumption. Fortunately, recent models incorporate technologies designed to limit this expenditure, by switching to deep sleep mode until a device is connected.
Should I always unplug?
Beyond the simple question of energy, leaving a charger permanently plugged in exposes it to variations in mains voltage. These fluctuations, although rare, can accelerate wear and tear on internal components. While modern chargers are designed to withstand these hazards, cheap or uncertified models present a real danger, with an increased risk of overheating or even fire.
Another sign to look out for: a charger that heats up abnormally, makes a noise or shows signs of deterioration should be replaced immediately. In this case, it is imperative to unplug the charger and stop using it. The expert’s answer is nuanced. While recent chargers are generally safe and consume little energy, unplugging is still the best option for limiting waste and extending the life of the device. It’s also a simple way of reducing your electricity bill and your ecological footprint.
On the other hand, old, damaged chargers or chargers of dubious quality are particularly urgent. These need to be monitored and disconnected systematically to avoid any risk. In the final analysis, leaving your charger plugged in is not catastrophic for a modern household equipped with certified equipment, but this small, harmless gesture, multiplied on a population scale, represents a considerable amount of wasted energy every year. By unplugging your chargers, you’re taking part in a collective effort to save energy, without giving in to psychosis. We still need to be vigilant: opt for certified chargers, monitor their condition, and adopt the reflex of unplugging as soon as possible. It’s a simple thing to do, for the sake of safety and the planet.
