[ekhalili]

I have a friend who insists that when the microwave or cell phone charger is plugged in, that it has a significant effect on his electrical bill. This got me thinking, what exactly is the usage on an outlet when the microwave or charger are just plugged in and not in use? Does a cell phone charger really make an impact on your electrical bill? I never thought about appliances just being plugged in as using power, so I would like to know so that I can make better educated decisions as to what I leave plugged in, and what I don't. If I should unplug my microwave every time I am done using it, then I will certainly do so! Thanks!

[Stratmando]

Cell chargers are negligible, TV Needs contant power to allow Remote control to work, Microwave, and many other things need power for Time and even the frequency of the electric for reference, clocks.
I saw on TV someone said to unplug a Toaster to save Power. That's a croc. They draw nothing unless toasting. May insure no fire?

[ballengerb1]

Your microwave requires power for the touch pad and clock to operate but usage is very small when not in use. I do keep my TV, DISH, stereo and VRC on a power strip so I can kill them all with one switch. You would likley save more money on power by replacing your AC is over 10 years old, same for refrigerators and freezers.

[hkstroud]

Well, I kind of poo-pooed the cell phone charger thing. I just checked a couple.

They both read input 120-240 V 50-60 hrtz 0.2 amp.

120V X 0.2 amp = 24 watts

24watts X 24 hrs X 30 days = 17280

17.28kW X $.15 (including taxes) = $2.59 per month

$2.59 X three or four cell phones and I'm paying the bill.

Damn right, unplug the thing.

[stanfortyman]

HK, that is the max input. For something to have input current that must also be output.
These are basically transformers. The power they draw themselves is negligible. Their job is to convert one voltage to another. The charging circuitry is what will draw the power.

I have a Kill-A-Watt. I just tried an old Moto V3 charger, an IBM Thinkpad power supply, and a Sony PSP charger, all NOT plugged in to their appliance.
ALL three read "00" Watts and VA.

My Wife's Pantech cell phone charger is rated at 0.3a input and 5v/700mA output.
In charge mode it is drawing a whopping 3 watts and 5VA.
Unplug the phone and it goes to "00" watts.

MYTH: Busted!

[hkstroud]

Got to disagree. Well at least a little bit. Don't know what the draw is when not charging but there must be some. Haven't measured but put you hand on it and feel the heat.

[stanfortyman]

Maybe all the ones I tried are switching power supplies.

So I tried a big fat 800mA Radio Shack wall wart. 22w input.
Terrible power factor of around .20
NO load: 1 watt, 8 va

[hkstroud]

Brings up an interesting question. What's happening out at the transformer on the pole when I turn out all the lights. Is the transformer still consuming some power?

[ekhalili]

Wow. Thank you guys for all the info. I am amazed that only 24 hours later there are this many replies. It seems that the effect, even if there is one, is not very big. I like the idea of using power strips, which I do anyway for all my computer appliances, but that wouldn't work as well in the kitchen.

Do you think a microwave with just the LED lights running is going to add an extra 5 or 10 bucks to the bill? It doesn't seem so. Thanks again for all the input, and by all means keep it coming if anyone has more to add. Thanks!

[hkstroud]

No, their cost is so small that even a cheap guy like me can't complain. Your door bell cost a lot more.