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: Windshield Wipers
Turn the wipers on by pressing the lever up or down.
With intermittent wiper
Variable-speed intermittent wipers
Set the lever to the intermittent position and choose the interval timing by
rotating the ring.
With auto-wiper control
Auto-wiper control
When the wiper lever is in the
...
Mazda 6 Owners Manual: Input/turbine speed sensor removal/installation
1. Disconnect the negative battery cable.
2. Remove the battery and battery tray.
3. Remove the air cleaner component. (See INTAKE-AIR SYSTEM
REMOVAL/INSTALLATION.)
4. Disconnect the input/turbine speed sensor connector.
5. Remove the input/turbine speed sensor.
6. Apply ATF to a new O-ring ...