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: Floor covering
FRONT FLOOR COVERING REMOVAL/INSTALLATION
1. Disconnect the negative battery cable.
2. Remove the front seats. (See FRONT SEAT REMOVAL/INSTALLATION.)
3. Remove the rear seat.
4. Remove the front scuff plates.
5. Remove the rear scuff plates.
6. Remove the console.
7. Remove the front side tri ...
Mazda 6 Owners Manual: Filament inspection
1. Turn the ignition switch to ON position.
2. Turn the rear window defroster switch on.
Caution
Directly touching the rear window defroster filament with the lead
of the voltmeter will damage it. Wrap aluminum foil around the end of the
lead and test the filament by touching it with the ...