Ticket #255 (closed defect: fixed)
battery voltage scale is not correct
|Reported by:||laforge@…||Owned by:||michael@…|
|Component:||kernel||Version:||current svn head|
|Cc:||sean_chiang@…, buglog@…, speedevil@…||Blocked By:|
|Blocking:||Estimated Completion (week):|
Since we don't have a coulomb-counting battery gas gauge, we cannot give proper
Our current battery percentage reading is based on battery voltage, and uses a
linear scale between 2.8 and 4.2V (see drivers/i2c/pcf50606.c:battvolt_scale()).
This scaling is obviously wrong and just a 'proof of concept' scale.
Somebody needs to do proper charge/discharge measurements and come up with a
non-linear algorithm expressing estimated battery life based on present battery
This needs a lot of experimentation/measurement, as well as a couple of
calculations. Please provide me either with a patch against battvolt_scale(),
or give me a mathematical formula expressing battery lifetime percentage as
function of terminal voltage.
- attachments.mimetype changed from text/plain to application/octet-stream
- Owner changed from tony_tu@… to michael@…
- Status changed from assigned to new