User talk:Speedevil/Ohm
This tar file for the n900 is a simple script that monitors battery impedance.
It has two modes. If called with no argument, it makes 10 measurements taking 20 seconds each, and then outputs an average of those measurements in a human readable form.
If called with an argument, it outputs every 200s the averaged measurement of impedence and voltage.
The top trace is a very old battery, perhaps 500 cycles. The middle is a similar battery, but that has been kept in the freezer much of the time, and experienced 20 cycles. The low trace is one that was purchased from ebay last week.
I intend to develop this into two simple applications - one that presents a best guess of battery remaining lifetime at the instant it's run, without relying on any history.
The second which monitors the battery over one full cycle, possibly able to run in the background normally without any significant extra power demand using the existing loads to monitor the state.
The battery impedance is an important factor. It is as important as the capacity, because a battery with relatively good capacity at normal drains may sag to the point of immediate shutdown when loaded heavily.
This is both of use to users to see how likely their battery is to need replacement soon, and to other OS developers that may be wanting to tune behaviour for real battery behaviour over time.
- This page was last modified on 3 August 2011, at 19:56.
- This page has been accessed 1,376 times.