SerpApi.Org
Walk through almost any home, and you'll find them: chargers left plugged into the wall, waiting for a phone that isn't there. It's one of those habits that feels harmless, but it raises two separate questions: one about your electric bill, and another about safety. To settle both, I spoke to Dan DiClerico, director of the Home Improvement & Outdoor Lab.
The short answer? An idle phone charger isn't the energy villain it's often made out to be, but that doesn't mean every charger in the house gets a pass.
The real distinction is the type of charger in question.
Does leaving your charger plugged in raise your electric bill?
This is a valid concern—it just doesn’t really apply to phone chargers. "When you add up all the vampire power consumed by electronics throughout the home, it can account for as much as 10 percent of your annual electricity bills," DiClerico says. "That could be a couple of hundred dollars a year."
Vampire power, also called standby power, is the electricity devices sip even when they're idle or off, and the biggest offenders are things like TVs, gaming consoles, and cable boxes. "Phone chargers are lower on the list of energy sucks, so keeping them plugged in is probably only costing you a few dollars a year," DiClerico says.
Is it safe to leave a charger plugged in all the time?
It's not a major hazard, but it's not doing the charger any favors, either. "We still recommend unplugging all phone chargers, since the constant flow of electricity, even at a low current, puts constant strain on their internal parts, leading to premature failure," DiClerico says.
In other words, the habit is less likely to burn your house down than to quietly kill the charger itself.
What about power tools and e-bike chargers?
This is where the advice gets non-negotiable. "It's essential to unplug larger lithium-ion battery chargers, like those for power tools and e-bikes, since they can be quick to overheat if damaged or left on a charger for too long, leading to a serious fire hazard," DiClerico says.
Fire officials echo this point: guidance from agencies, including the U.S. Fire Administration and the Consumer Product Safety Commission, calls for charging these batteries attended (as in, not overnight or while you’re out running errands), plugged directly into a wall outlet rather than a power strip, and unplugging them as soon as they're full.
The bottom line
Leaving a phone charger plugged in costs you a few dollars a year and shortens the charger's lifespan, so unplugging is a good habit. But for lithium-ion chargers powering tools, e-bikes, and scooters, it's a safety rule. Those come out of the wall the moment the battery is charged.
