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: Service warnings
HANDLING REFRIGERANT
Avoid breathing air conditioning refrigerant or lubricant vapor.
Exposure may irritate eyes, nose and throat. Also, due to environmental
concerns, we urge use of recovery/recycling/recharging equipment when
draining R-134a from the air conditioning system. If accide ...
Mazda 6 Owners Manual: Engine coolant
ENGINE COOLANT LEVEL INSPECTION
Verify that the coolant level in the coolant reservoir is between the F and L
marks.
If the engine coolant level is below L, remove the radiator cap and add
coolant. (See COOLING SYSTEM SERVICE WARNINGS.)
ENGINE COOLANT REPLACEMENT
Warning
Drain the ...