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: Outside Temperature Display (Without Multi-information Display)
When the ignition is switched ON, the outside temperature is displayed.
NOTE
Under the following conditions, the outside temperature display may differ
from the actual outside temperature depending on the surroundings and vehicle conditions:
Significantly cold or hot temperatures.
Sudden ...
Mazda 6 Owners Manual: Information display removal/installation
1. Disconnect the negative battery cable.
2. Remove the center panel module. (See CENTER PANEL MODULE
REMOVAL/INSTALLATION.)
3. Remove the LCD unit. (with car-navigation system) (See LCD UNIT
REMOVAL/INSTALLATION.)
4. Remove the center box. (without car-navigation system)
5. Remove in the or ...