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: Air intake actuator inspection
1. Connect battery positive voltage to terminal D or F and ground to terminal
F or D of the air intake actuator.
2. Verify that the air intake actuator operates as shown below.
If not as specified, replace the air intake actuator.
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Mazda 6 Owners Manual: Turning the Engine Off
WARNINGDo not stop the engine while the vehicle is moving: Stopping the
engine while the vehicle is moving for any reason other than in an emergency is
dangerous. Stopping the engine while the vehicle is moving will result in reduced
braking ability due to the loss of power braking, which coul ...