Laptops are the most power-hungry of the nomad's communications devices; phones and tablets require much less power.

There are several techniques for successful laptop use on the road.

This advice will likely come too late.

If you don't already own a laptop, consider buying one that uses less power. One crude measure will be the wattage rating of the AC adapter. It really tells us the peak power use but there is usually a relationship between peak and average power.

Sometimes the adapter will give watts on the back label or in the documentation. In the example on the right, this Dell laptop adapter does say it is a 90W charger.

If the label only shows output in volts and amps we can use Ohm's law to calculate watts. In this case, 19v x 4.62A = 87.78W, which is in line with the 90W number on the label.