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: Diagnostic trouble code number inspection
1. Remove the glove compartment.
2. Short the A/C check connector to the GND terminal using a jumper wire.
3. Shine a 60 W incandescent light from a height of approximately
100 mm {3.9 in} onto the solar radiation sensor.
Note
When incandescent light does not shine on the solar radiatio ...
Mazda 6 Owners Manual: General procedures
PRECAUTION (FRONT AND REAR AXLE)
Wheel and Tire Removal/Installation
1. The removal and installation procedures for the wheels and tires are not
mentioned in this section. When a wheel is removed, tighten it to 88-118 N·m
{9.0-12.0 kgf·m, 65.0-87.0 ft·lbf}
Brake Line Disconnection/Connecti ...