Do Chargers Waste Electricity When Not in Use?by William Jensen
Some people find it convenient to leave chargers plugged into electrical outlets at all times, simply disconnecting electronic devices or removing batteries when they finish charging. Unfortunately, many such chargers waste electricity when they remain connected to outlets but not in use. The waste of electricity increases pollution, raises electric bills and necessitates the construction of additional power plants. Fortunately, it's almost always possible to remedy this problem without much difficulty.
Most cellular phone chargers lack on/off switches, so they continue to draw electricity when not in use. Considering that billions of people worldwide now use cell phones, the total electricity waste caused by this type of charger provokes great concern. The Natural Resources Defense Council recommends unplugging such chargers whenever they aren't actually charging cell phones. An alternative is to turn them on and off with a power strip or an outlet controlled by a wall switch. This will also protect them from power surges.
Notebook and laptop charging adapters waste power when disconnected from a notebook computer, according to the U.S. Department of Energy. Like cell-phone chargers, they continue to use electricity unless unplugged from the electrical outlet. Some have indicator lights to show when they draw power; others do not. If the laptop computer has no battery or it no longer accepts a charge, always disconnect power when the computer is not in use.
Some household battery chargers that charge removable batteries (for flashlights, clocks, radios, etc.) also waste electricity when not in use. The U.S. Department of Energy urges people to unplug battery chargers after finishing a charge or removing the batteries. If the charger does not have a power switch or has an indicator light that always remains on, it will probably waste electricity when not in use. Consider using a timer to shut a battery charger off after it finishes charging the batteries adequately.
A range of other portable electronics, machines and toys also use electrical chargers to energize their built-in rechargeable batteries. Energy Star indicates that chargers for shavers, power tools and small appliances often waste significant amounts of power while not connected to a device. The only way to verify that a charger draws electricity when not in use is to connect it to a wattage meter that plugs into a standard electrical outlet and use it to check the power consumption.