A low level of electrolyte fluid will cause the battery to discharge quickly.

Inspect the electrolyte level at least once a week. If it is low, remove the caps and add enough distilled water to bring the level between the upper and lower level (illustration).
Do not overfill.
Examine the specific gravity of the electrolyte with a hydrometer, especially during cold weather. If it is low, recharge the battery.
Battery Maintenance
Battery RechargingMazda 6 Owners Manual: Adjusting the Vents
Directing airflow
To adjust the direction of airflow, move the adjustment knob.
NOTE
When using the air conditioner under humid ambient temperature conditions,
the system may blow fog from the vents. This is not a sign of trouble but a
result of humid air being suddenly cooled.
The air ...
Mazda 6 Owners Manual: Key reminder switch inspection
1. Disconnect the negative battery cable.
2. Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION)
3. Disconnect the key reminder switch connector.
4. Inspect for continuity between the key reminder switch terminals using an
ohmmeter.
If not as specified, replace the key reminder ...