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: Storage Compartments
WARNING
Keep storage boxes closed when driving: Driving with the storage
boxes open is dangerous. To reduce the possibility of injury in an accident or a
sudden stop, keep the storage boxes closed when driving.
Do not put articles in storage spaces with no lid: Putting articles
in storage sp ...
Mazda 6 Owners Manual: Condenser removal/installation
4SD
1. Disconnect the negative battery cable.
2. Remove the rear package trim.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
5HB
1. Disconnect the negative battery cable.
2. Remove the liftgate lower trim.
3. Remove in the order indicated in t ...