Chapter 13. Power consumption

Between christmas and new year 2004, I bought an energy counter. You plug it into the socket and attach the desired device to it - and it displays which voltage, amperage, power etc. it uses.

The first thing I tested was my Travelmate here are the results:

Table 13.1. Power consumption of my Travelmate

DeviceStateConsumption in Watt
AC adaptornot plugged into laptop6 W
connected with off-state laptop, not loading0 W
Laptoploading, 1.6GHz37 W
loading, 600MHz37 W
loaded, 1.6GHz32 W
loaded, 600MHz27 W
loaded, LCD off, 1.6GHz27 W
loaded, LCD off, 600MHz22 W

Note

The "loading" states were mesured when the battery was loaded about 50%. With increasing percentage (from 85 or so) the laptop uses less power, even when loading.

Note

It seems not to make a difference if the machine is idle or compiling something - it uses the same power.

All in all: I never thought the laptop would consume so few power. My desk light needs 20W, and with 600MHz and LCD off the notebook is nearly equal.

For those who wonder: In Germany we have a voltage of 250V.