Why you should unplug your phone charger after use?

Fire risk

Charging devices, especially older or faulty ones, can generate heat and create fire hazards. Although modern smartphones have safeguards to prevent accidents, defective or outdated chargers can still pose risks.

Sarah-Jane Knox, consumer affairs manager at the Insurance Council of New Zealand, said in an interview with Radio New Zealand that such fires were often caused by incorrect charging practices. This could include using the wrong charger, charging a physically damaged device, or overcharging, she added.

To avoid such risks, the London Fire Brigade advised, "Don’t leave items continuously on charge after the charge cycle is complete, it's best not to leave your phone plugged in overnight for example. Never cover chargers or charging devices, that includes using your laptop power lead in bed," as reported by Wales Online.

A phone plugged in to a power source. Photo by Pexels

"Vampire energy" consumption

Phone and laptop chargers often remain plugged in even when not in use, contributing to "vampire power" – a low-level, continuous energy draw. Glen Farivar, a lecturer in power electronics at the University of Melbourne, told The Conversation that this idle energy consumption leads to unnecessary power waste.

According to the U.S. Department of Energy, unplugging unused chargers and electronics can save households up to $100 annually.

Risk of electric shock

Inexpensive chargers are often made with substandard wiring, insulation, and plastic materials, which can lead to failure, Sergey Nikoli, president of Product Air Heating & Cooling, told lifestyle magazine Martha Stewart.

"Damaged chargers are the riskiest because cracked casings, frayed cables and loose plugs can easily spark or short out."

Battery lifespan reduction

Leaving your phone plugged in overnight can shorten the lifespan of its battery. Older models continue drawing small amounts of power to maintain a full charge, a process known as "trickle charging," which can degrade battery life over time, according to tech site PCMag.

Newer devices feature optimized charging systems, but this process can still contribute to battery wear. As charging cycles generate heat, the battery's effectiveness gradually diminishes. Over time, battery damage can lead to costly repairs, especially in newer models where battery access requires professional servicing, which can cost over $150, Wales Online reported.

Risky habit

Leaving chargers plugged in may also encourage other unsafe habits. If you neglect to unplug your charger, you may forget to unplug more hazardous items, such as irons or space heaters.

"It’s a useful skill to do such things just automatically," Nikoli said.