Leaving a phone charger plugged into the wall has become second nature for many people. Whether it’s beside the bed, on the kitchen counter, or at your work desk, chargers often stay connected to an outlet 24 hours a day—even when there’s no phone attached.
It seems harmless, but is it actually safe?
According to electricians and electrical safety experts, leaving a charger plugged in isn’t always dangerous, but it isn’t always the best habit either. While modern chargers are designed with safety features, keeping them plugged in unnecessarily can waste electricity, shorten the charger’s lifespan, and, in rare cases, increase the risk of overheating or electrical problems.
Here’s what you should know before leaving your charger plugged in all the time.
How Phone Chargers Actually Work
A phone charger converts the alternating current (AC) from your wall outlet into the low-voltage direct current (DC) your smartphone or tablet needs.
When your device is connected, the charger supplies electricity to recharge the battery.
When nothing is plugged into the charger, it doesn’t stop working completely. Instead, it continues drawing a tiny amount of electricity known as standby power or phantom power.
Modern chargers are far more efficient than older models, but they rarely consume zero electricity while plugged in.
Do Chargers Use Electricity When Nothing Is Charging?
Yes—but very little.
Most modern USB chargers consume only a tiny fraction of a watt when left plugged in without a device attached.
For a single charger, the annual cost is usually only a few cents depending on local electricity prices.
While the financial impact is minimal, the energy use becomes more significant when multiplied across millions of chargers left plugged in around the world every day.
