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: Input/turbine speed sensor inspection
Caution
Water or foreign objects entering the connector can cause a poor
connection or corrosion. Be sure not to drop water or foreign objects on the
connector when disconnecting it.
1. Disconnect the negative battery cable.
2. Remove the battery and battery tray.
3. Remove the air cl ...
Mazda 6 Owners Manual: Front door unit removal/installation
1. Remove the front door glass.
2. Remove the inner handle.
3. Remove the front door speaker.
4. Disconnect the power window motor connector, front door lock actuator
connector, power outside mirror connector.
5. Remove the door harness from the front door unit.
6. Remove the bolts.
7. Rem ...