Do plugged in chargers always use up energy?

Question

I always make sure that all chargers with no device attached (mostly laptop and phone chargers) are unplugged so that they don't use up electricity. I guess it used to be a reasonable approach. I was wondering if it sill holds with modern devices. In other words: do plugged in chargers use up electricity even without any device attached?

Answer 1

This is one of those questions without any clear answer.

One person will say they measured the draw, and came up with .05 watts per device, which adds up to something like 5-6 cents over a year. Someone else will come around and say "But my device charger gets WARM, I measured it at 5 watts, so that means it'll cost $5 per device, times 10 chargers, that's $50!!!!

Both of these made up people aren't wrong, but neither are really right either. In this case the phrase "Your Mileage May Vary" is really quite applicable.

So I'd say the short answer is "it depends". Phantom draw has gotten considerably better over the years as the charger industry has gotten better at this. There's actually an initiative to reduce standby power called the One Watt Initiative that aims to reduce standby power of appliances (and apparently chargers) to less than 1 watt by 2005, and .5 watts by 2013.

In other words, if you have some old chargers, you may want to look into replacing them with something newer. If you have newer ones, they might not be as much of an issue. But unless you either measure the usage yourself or lookup the specifications of standby power usage, it's not possible to generalize since the power usage varies by factors of 10 or maybe even 100.

Answer 2

Yes they do - they waste energy checking to see if they have a device attached that they need to charge, it’s not the penny a year but if you take the number of chargers for all your devices left plugged in 24/7 and multiply by the number of households in the country it leads to about the output of 1 power station...

The excuse usually given “if I take the charger out if the socket I will loose it”....

Answer 3

The answer is yes they consume energy. The easiest way to tell is feel them, they are usually warm that is wattage being consumed. Switching power supplies use transistors to charge capacitors, both have leakage currents so they are running at a low level because of the leakage. Transformer type supplies even if ac also have losses the loss in this case is from eddy currents in the transformer and again the thing feels warm to the touch. The amount of power is minimal but there is some consumption of power even with nothing attached. I have used my thermal camera to show this to my grandson that thinks it’s a status symbol to have a dozen wall warts on power strips. Some are much warmer than others.