Laptop power meter

[Robert Wheeler]

I have 40 Compaq laptops (Evo N115 and Evo N1000c) each equipped with two Valence 130HL01 batteries. These are external pancake batteries that together give me 20 additional hours of run time.

We have been unable to develop a satisfactory way of displaying the actual internal battery level, because the Valence battery makes the laptop believe it is plugged into an AC power source.

I have been able to write an app using WMI that reads the battery level even with the Valence (or an AC source) plugged in, however, in the following situation, the battery lies and continues to report 100% charge:

If the laptop is plugged into a Valence, and the Valence is plugged into a power source, and the laptop and Valence(s) attain 100% charge, then the AC power source is unplugged.

The infernal battery will continue to report 100% charge until the computer switches off, completely discharged.

If I unplug and replug the Valence once the AC is removed, then the internal battery will report the actual power level.

Has anyone else run into a similar situation, have a better way to read the power level? Even "reset" the internal battery to allow it to report properly?