Notebook battery drain meter (NDM) is a freeware very simple application running under Windows platform (tested on XP and 7, requires WMI - should be present on current Win OSes). It solves a problem of observation and alerting of NB power consumption when running on batteries. NDM works as follows:
Decompress the app into desired directory and run.
NDM creates TRAY icon, which shows current power drain from battery in Watts.
Main window open first time and allows to configure alerting tray color (when done click Save to tray).
There is possibility to set up Watt limit to tray icon background color change to Green, Yellow, Red.
It also can blink from certain limit.
Main window can shown / hidden by click on tray icon. Right click opens menu with Exit application item.
Your settings are stored in standard ini file, autostart can be selected by writing to the registry.