Charging phone from switched off computer

d12345 · 4 February 2014 at 12:44PM

I have a second computer that I only use for a specific program that does not run on 64 bit windows 8.1.

It also shares my second monitor, I have 2 monitors on my computer.

I usually leave this old computer plugged in but shut down but I happened to leave my phone plugged in via a USB lead and noticed that my phone is still charging even although the computer is off and shut down but still plugged into the wall socket.

A quick question, is charging my phone using my switched off computer using less or more electricity than using my phone charger?

lee111s · 4 February 2014 at 12:57PM

Unltimately it's charging the same battery with the same amount of power, so on that front, exactly the same. However as your computer is drawing power when it's in standby mode it's also using electricity and will be costing. Turn off the computer at the wall and use your phone charger.

matelodave · 4 February 2014 at 4:18PM

A phone charger is a lot more efficient than leaving a computer on standby or even plugged in - the power unit will still draw current even if the phone isn't plugged in. Get yourself a plug-in electricity monitor and have a check at how much power some stuff draws when it's on standby - you'll be surprised. Just one watt on all the time will consume 8.76kwh a year which is just over £1 a year. Not a lot I grant you but add them all up and you easily save £25-£50 or more a year by unplugging stuff that you think is turned off or sitting on standby. Even a phone charger draws some power even if the phone isn't connected.