Leaving wall chargers of gadgets such as smartphones, tablets, laptops and more plugged in will not drive up energy bills.

HowToGeek has tested chargers of popular devices such as iPhone, MacBook, iPad, Chromebook, Android phones and more using a Kill A Watt meter and found that when they are plugged on individually they consume 0.0 watts of power.

"Having heard about the evils of vampire power and the need to unplug devices when we're not using them, we were surprised to see that not a single charger used a detectable amount of vampire power when it was plugged into an outlet," per HowToGeek.

However, the wall chargers do consume some energy when plugged in but the Kill A Watt meter cannot detect them. HowToGeek took their test to another step and plugged a power strip with six wall chargers to the Kill A Watt meter to see how much electricity all the chargers consume in total.

The meter showed a reading of 0.3 watts for all the six chargers plugged in to the power strip.

If all the six chargers are plugged in 24 hours for 7 days a week for one complete year then these chargers combined will consume 2.628 kilowatt hours (kWh) of power. In the U.S., the average cost of electricity is 12.98 cents for each kWh consumed. In monetary terms a user will have to pay 34.1 cents for one entire year.

HowToGeek suggests that the test was neither scientific nor precise. Some chargers may consume more power while other less. It is also unlikely that a user will leave a wall charger plugged in for a long period of a year.

In the modern world, most of the households have a number of smartphones, tablets and laptops that need charging regularly. Many people are concerned that leaving the wall chargers for these gadgets plugged in will result in higher electricity bills. However, the HowToGeek test shows that leaving wall chargers plugged in will not burn a hole in the user's pockets.

Photo: Karl Baron | Flickr