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: Dtc table
DTCs are common for present and past malfunction diagnosis.
Note
When DTCs not shown in the DTC table are displayed, replace
the SAS unit.
If the air bag system warning light does not illuminate or
remains illuminated when the ignition switch is turned to ON position,
i ...
Mazda 6 Owners Manual: To Resume Cruising Speed at More Than 25 km/h (16 mph)
If some other method besides the OFF/ CANCEL switch was used to cancel cruising
speed (such as applying the brake pedal) and the system is still activated, the
most recent set speed will automatically resume when the RESUME/
switch is pressed.
If vehicle speed is below 25 km/h (16 mph), incre ...