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: Uniform Tire Quality Grading System (UTQGS)
This information relates to the tire grading system developed by the U.S. National
Highway Traffic Safety Administration for grading tires by tread wear, traction,
and temperature performance.
Tread Wear
The tread wear grade is a comparative rating based on the wear rate of the tire
when tes ...
Mazda 6 Owners Manual: Blind Spot Monitoring (BSM) Warning Indicator Lights/Display Indicator/ Blind
Spot Monitoring (BSM) Warning Beep
The Blind Spot Monitoring (BSM) or Rear Cross Traffic Alert (RCTA) system notifies
the driver of the presence of vehicles in adjacent lanes or at the rear of the vehicle
using the Blind Spot Monitoring (BSM) warning indicator light, the warning sound
and the display indicator (vehicles with mu ...