Cell phone chargers draining your electric?

House Doctor | Gary Dymski

November 25, 2004

We have several cell-phone transformers we keep plugged into an outlet. When we recharge cell phones, electricity is being used. But what about when the cell phone has been removed? Is the transformer still using electricity? This might not be a big deal, but I do not want to pay for electricity if I am not using it.
-- Anthony Nunziato, Dix Hills

Having the recharging unit plugged into an outlet all the time is indeed costing you money. Even though the unit is in standby mode, it still draws power.

Houses that have so many electrical items on standby power are said to be "leaking" electricity. A few years ago, a study by students and scientists from the University of California at Berkeley and Lawrence Berkeley National Laboratory determined that homeowners could significantly reduce energy usage by eliminating such sources of standby electricity.

House Doctor Recent columns

One student, who studied 10 California homes, determined that the largest users of standby energy were the transformers that recharge cell phones and hand-held video games and computer peripherals, such as printers and scanners.

According to the study, a cell phone recharger draws about 0.3 watts of electricity when not in use. The largest user of standby energy is a VCR, 12 watts. Studies show that standby electricity in a home can run between 50 and 450 kilowatt hours a year. On the high end, that's comparable to running a second refrigerator for about eight months.

For ways to reduce energy usage, visit the Home Energy Saver Web site, www.home energysaver.lbl.gov, which is sponsored by the U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA).