PowerGuard – battery monitoring for Windows Mobile
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How does it work?
The main application has six tabs:
| 1. Text | : | A textual representation of actual battery properties. |
| 2. Graphs | : | A graphical representation of actual and past battery properties. |
| 3. Life | : | A textual and graphical representation of remaining battery life (registered version only). |
| 4. Control | : | Via this tab, the user can configure the behaviour of PowerGuard, such as update frequency. |
| 5. Log | : | Via this tab, the user can configure the logging behaviour of PowerGuard (registered version only). |
| 6. About | : | Information about PowerGuard, such as version number, and link to the PowerGuard website. |
Please note that when the battery is charging, the current has a positive sign. Conversely, a negative current indicates that energy is drained from the battery. The user can change this default behaviour on the control tab.
PowerGuard estimates remaining battery life by using linear regression (Linear Least Squares). It takes usage history into account when predicting future battery drain. Therefore, the estimate is likely to be better when there are more measurements. PowerGuard only measures battery status when the device is switched on and when it is not in standby. All in all, prediction accuracy increases when update frequency on the control tab is increased, the device has shorter/no standby or off time, and it has a longer measurement history. Especially when measurement has just started, there may be a substantial difference between subsequent lifetime predictions.