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: Fuel line pressure inspection
Warning
Fuel line spills and leakage are dangerous. Fuel can ignite and
cause serious injuries or death. Fuel can also irritate skin and eyes. To
prevent this, always complete the BEFORE REPAIR PROCEDURE. (See BEFORE
REPAIR PROCEDURE.)
Caution
Disconnecting/connecting the quick r ...
Mazda 6 Owners Manual: Inspecting Coolant Level
WARNING
Do not use a match or live flame in the engine compartment. DO NOT ADD
COOLANT WHEN THE ENGINE IS HOT: A hot engine is dangerous. If the engine has
been running, parts of the engine compartment can become very hot. You could be
burned. Carefully inspect the engine coolant in the coola ...