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: Compression pressure
COMPRESSION INSPECTION
Warning
Hot engines and oil can cause severe burns. Be careful not to burn
yourself during removal/installation of each component.
1. Verify that the battery is fully charged.
Recharge it if necessary. (See BATTERY INSPECTION.)
2. Warm up the engine to the no ...
Mazda 6 Owners Manual: Trunk end trim removal/installation
4SD
1. Remove the fasteners.
2. Pull the trunk end trim upward, then disengage clips A, pins B, and hooks.
3. Remove the trunk end trim.
4. Install in the reverse order of removal.
5HB
1. Pull the trunk end trim upward, then disengage clips A, pins B, and hooks.
2. Remove the trunk end tr ...