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: Fuel Gauge
The fuel gauge shows approximately how much fuel is remaining in the tank when
the ignition is switched ON. We recommend keeping the tank over 1/4 full.
If the fuel level is low, and
turn an amber color. Refuel as soon as possible.
Refer to Taking Action.
NOTE
After refueling, it m ...
Mazda 6 Owners Manual: Front passenger air bag deactivation indicator light
This indicator light turns on to remind you that the front passenger front and side air bags and seat belt pretensioner will not deploy during a collision.
If the front passenger occupant classification sensor is normal, the indicator light turns on when the ignition is switched ON. The ...