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: Supplemental Restraint System Components
(With Front Passenger Occupant Classification System)
(Without Front Passenger Occupant Classification System)
Driver/Front passenger inflators and air bags
Roll-over sensor (some models), crash sensors, and diagnostic module (SAS
unit).
Seat belt pretensioners
Front air bag sensor ...
Mazda 6 Owners Manual: Abs (abs/tcs) hu/cm inspection
1. Disconnect the negative battery cable.
2. Connect the SST between the ABS (ABS/TCS) HU/CM and harness
connector with the ignition switch off.
3. Attach the tester leads to the SST and inspect voltage referring
the table below.
Terminal Voltage Table (Reference)
(Engine is idling, and co ...