Most people leave phone chargers plugged in for convenience, but they keep drawing electricity even when no device is attached. The transformer inside stays active, a phenomenon known as standby power. Typical idle draw ranges from 0.1 to 0.5 watts, equating to roughly 2–24 watt‑hours per day. Thus the plug remains active, preventing a true zero‑watt state.

That trickle adds up on a utility bill. Depending on regional rates, a single charger left idle can cost anywhere from 50 cents to $4 annually. Multiply that by dozens of chargers, tablets and handheld consoles, and standby loads represent 5‑10% of a typical household’s electricity use, according to Canadian data. Higher rates can push the upper estimate toward five dollars annually.

Consumers can curb the waste with a few simple steps. Energy‑efficient chargers that support multiple devices tend to draw less idle power. Plugging chargers into smart outlets lets users cut power remotely via an app. The cheapest fix remains unplugging or flipping the wall switch whenever the charger isn’t needed. Regularly inspecting cords for fraying or overheating also prevents wasted power and reduces fire risk.