Does a laptop recharger waste electricity when the laptop is not connected?

I have a laptop with a recharger (also known as an AC adapter), this is how it looks like:

enter image description here

When I disconnect my laptop from the charger, does it (the charger) still consume (waste) electricity?

EDIT:

I am trying to do math, how many kW I waste every year to keep my adapter plugged in the whole time. I tried to read how much watts does it take, but I am not good with that kind of stuff, so here is some info:

INPUT : 100-240V~50-60Hz 1.5A(1,5A)

OUTPUT: 19.5V(19,5V) --- 4.62A(4,62A)

Does this info help to do the math?

There is 8760 hours in year.

power-supply

Jaanus

Posted 2011-09-26T18:26:43.777

Reputation: 193

Apple provides some information about its power adapters in its environmental reports. The power adapter of a 2013 Macbook Pro 13 inch uses between 0.004W (100V) and 0.019W (240V) without load.

– Daniel Beck – 2014-01-28T14:13:54.157

Answers

Yes. Generally anything with a transformer in it will draw at least some power when plugged in. See here for more details on the types of devices that will typically use power even when off. The only thing that will keep a device from drawing standby power is if you actually break the circuit that the device is plugged into.

MaQleod

Posted 2011-09-26T18:26:43.777

Reputation: 12 560

But how much? I added some text from the adapter, I am not sure if those are right numbers, since I only found volts. – Jaanus – 2011-09-27T05:01:16.587

2@Jaanus you'd need to measure it. The exact amount of idle current is dependent on the the implementation details. Mostly in that cheaper devices will draw more power for the save level of functionality. Unfortunately for consumer level hardware this is easier said than done because idle power levels are similar to both the base error level and granularity of inexpensive power meters like a killawatt. – Dan is Fiddling by Firelight – 2011-09-27T12:58:01.870

Yes, not a whole lot but over time it does add up. It can also wear out the transformer sooner.

See http://electronics.howstuffworks.com/everyday-tech/plug-in-transformer.htm for more info.

bryan

Posted 2011-09-26T18:26:43.777

Reputation: 7 848

2modern laptop power supplies are switching power supplies – Journeyman Geek – 2011-09-26T22:46:40.080

But how much? I added some text from the adapter, I am not sure if those are right numbers, since I only found volts. – Jaanus – 2011-09-27T05:01:35.463

The article I refer to shows you how to calculate it. – bryan – 2011-09-27T05:06:21.790

I just did a test with my P3 watt meter. One old DELL adapter (10+ years, for Latitude P3 650) uses 1.3W while the laptop is not connected. However, a recent HP adapter (2+ years) uses 0 W (at least from P3 watt meter reading).

Codism

Posted 2011-09-26T18:26:43.777

Reputation: 845