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: Rear brake (disc) removal/installation
1. Remove in the order indicated in the table.
2. Install in the reverse order of removal.
3. After installation, depress the pedal several times, rotate the wheel by
hand, and verify that the brake does not drag.
Disc Pad Installation Note
1. Turn the manual adjustment gear counterclockwi ...
Mazda 6 Owners Manual: Locking, Unlocking with Auxiliary Key
Turn the auxiliary key toward the front to lock, toward the back to unlock.
To lock
All doors lock automatically when the driver's door is locked using the auxiliary
key.
To unlock
The driver’s door unlocks when the auxiliary key is turned briefly to the unlock
position and then immediatel ...