Well, the easy way to tell is to feel the adaptor after it's been plugged in (but not connected to anything) for a while, it'll be warm.

Of course he could have one of Nokia's switching adaptors (hey, they're only $60 ).

If the device is using so little electricity that the device can't measure it, for all intents and purposes of this thread, it's 0.

But YOUR statement of zero facts is still wrong.

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Your statement had two point of what you thought were fact.

1) there were zero watts
2) there were zero amps

BOTH were ZERO as factual.

If you would have initially stated that for all "intents and purposes" the draw was zero, we wouldn't be in this dispute, but that isn't what you initially stated now was it.

Your instrument is incapable of measuring the electrical current draw of the Nokia N8x0 charger at idle. The issue is with your measurement technique.

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I will measure the actual current consumption ( in milliamps ) of the two N800 AC adapters I have here and I shall report those values tomorrow for those who are curious. I won't say that ALL Nokia N8x0 chargers will be the same idle current as mine but at least we will have two measured values to work with so we will have FACTS (from two real N800 AC adapters measured with the proper test equipment). BTW- my test equipment is "tracable" to NIST (previously known as the National Bureau of Standards), so we can trust its accuracy. I am an instrumentation engineer so we can trust my techniques. I have been doing this for 35 years.

It will be in AC current, I will provide the value as RMS (root mean square) and I predict the current will be very small compared to a common household light bulb but it will not be zero.

FYI- The two chargers I have here for my N800's are both the same model number. They are Nokia # AC-4U.

These AC-4U, like most all contemporary AC adapters are "switchers". The term switcher classifies the power supply as one which "switches" or chops the power at high frequency (sometimes ~100,000 hertz) to achieve it's goal of converting one type of voltage - to another type. The older non-switchers are known as linear. Linear AC adapters can be rather easily identified by their size and weight relative to their power output. The linear power supplies are significantly heavier compared to a switcher. The reason for this is due to the fact that linear power supplies use laminated iron as a step-down transformer core material.

The Nokia AC-4U converts input voltages from 100-240 VAC (50 or 60 hertz) to 5VDC. To do this as efficiently as possible the incoming AC voltage is internally rectified (to DC) then charges an electrolytic capacitor (usually 170 to ~180 volts DC in the USA, ~340VDC in some other Countries). This high DC voltage is then "switched" thru a high performance transformer of copper wires around a small ferrite core. This is why these are called switching power supplies. Essentially the electrical DC energy is converted into magnetic energy at a high frequency. The ferrite material is required as the core because iron is too slow in response. The magnetic energy is precisely converted back into electrical energy at a much lower voltage ( 5 volts DC ). This is all done with great efficiency (approaching, or exceeding 90%).

Switching power supplies are more complex than non-switching power supplies but can be made very small for the same power conversion. The switchers also weigh a fraction of the non-switchers because the small lightweight ferrite parts in the high frequency transformer replace heavier laminated iron plates in transformers. Contemporary switching power supplies also take advantage of very low "on resistance" power MOSFET transistor technology which has significantly dropped in price recently.

Just about all new consumer electronic gadgets have small, lightweight, high efficiency "switching" power supplies.

The PS I got with my N810 is also an AC-4U.

OK, obviously I should have read the rest of this thread before jumping up to measure my idle current, as it appears better measurements will be coming soon anyway, but I got a reading of 0.001 mA; definitely less than 10 uA, but obviously not necessarily 1 uA. (Cheap consumer-grade DMM.)

Anyhow, 115 V and < 10 uA means less than 1 milliwatt.
Since a year is 10 kh, a year's energy consumption would be < 10 Wh, and for 10 cents / kWh, that's worth less than 0.1 cent per year.

Will look forward to an accurate measurement from xxM5xx.

On my laptop the manual advises to put the charger directly into a wall socket; not multi socket. Why is that? I rather stick it in a surge protector.

I'm using a AC-3E for my N810, and I have a multi-meter. How can I test the current output?

Also, please remember the subject remains "Leaving Charger Plugged In?". As I stated there are other reasons to unplug it. One reason why I don't like to unplug it is because I keep my NIT on and keep it charged so I can always have it right with me with maximum power not having to boot it up (takes a lot of electricity as well). However in the summer there is a lot of thunderstorms occuring from noon to early morning, and then I am careful to connect the adaptor on a surge protector instead.

It's just how it's written and has no special meaning or significance. It's always better to use a surge suppressor. A power strip with a switch provides the same "green" result as unplugging the power adapter from the wall outlet.

if i unplug the charger from my n800 but leave it plugged into the wall, is it still using power?

simple yes-no question

The simple answer, then, is "no". The more complex answer is closer to "yes". Read the thread.