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: Power brake unit removal/installation
1. Remove the master cylinder. (See MASTER CYLINDER REMOVAL/INSTALLATION.)
2. Remove the wiper arm. (See WINDSHIELD WIPER ARM AND BLADE
REMOVAL/INSTALLATION.)
3. Remove the cowl grille. (See COWL GRILLE REMOVAL/INSTALLATION.)
4. Remove the wiper motor. (See WINDSHIELD WIPER MOTOR REMOVAL/INSTAL ...
Mazda 6 Owners Manual: Front upper arm removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-sensor (axle side) and fix it to an appropriate pl ...