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: 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 ...
Mazda 6 Owners Manual: Fuel injector inspection
Operation Test
Carry out the Fuel Injector Operation Inspection. (See Fuel Injector
Operation Inspection.)
If not as specified, perform the further inspection for the fuel
injectors.
Resistance Inspection
Note
Perform the following test only when directed.
1. Turn the ignition s ...