The PwrDrain Gadget

This Sidebar gadget isn't quite "yet another power meter" for your laptop battery: while most power meters show the remaining battery charge (similar to the task bar icon that's included in Windows), this one shows the current power drain in real time.

Make sure to visit our FAQ!

Advantage of using PwrDrain

This means that if you start doing something that's power intensive, like turning on WiFi, turning up the display brightness, or plugging in lots of USB devices, you'll be alerted immediately about the increased consumption. Although this description might sound very techincal, it's actually very easy to use and really pretty, too!

The technology behind PwrDrain

This gadget is written entirely in HTML, CSS and JavaScript and is delivered without any binary code. In order to obtain the meter readings, the code instantiates ActiveX objects that are part of the Windows system.

The readings are obtained through Windows Management Instrumentation (WMI) which also provides the data for Performance Monitor included in Windows. In turn, the values provided by WMI are obtained from the computer firmware using the Advanced Configuration & Power Interface (ACPI). The gadget accesses WMI through the WMI Scripting API.

While most modern battery-powered computers and portable devices provide a power meter, even recent desktop computers don't have one. As a consequence, this gadget will not work on those types of machines. The easiest way to find out whether a particular machine provides a usable power meter is to run Performance Monitor (from Control Panel, System and Security, Administrative Tools) and make sure that when selecting "Power Meter" in the "Add Counters" dialogue the list of Instances isn't empty.

PwrDrain logo

The PwrDrain logo is © 2008 by Hillwalker under Creative Commons Attribution 2.0 Generic.