Continuous power consumption of laptop's power brick when in plugged in, not charging mode?

Modern laptops come with the facility of being used in a plugged in mode only, without overcharging the battery. So, in such a case, the power consumption through the adapter should vary according to the workloads being run on the laptop.

How to measure this, so as to know what wattage of power is consumed during the periods of low usage vs intensive usage?

Solution 1:

You need a Wattmeter to measure AC Adapter current under varying conditions.

There are reasonably economical wattmeters available.

Battery threshold is normally 80% (versus fully charged), so at 80 or 100% charge, the AC Adapter current draw will be about the same, and will be related more to computer load.

A wattmeter can help you here.

It will show average levels more than instantaneous levels, depending on the dampening within the meter. You may want a meter with a low power range to see your power level more clearly (a 100 watt Wattmeter won't show you much).