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 Requirements
Vehicles with catalytic converters or oxygen sensors must use ONLY UNLEADED FUEL,
which will reduce exhaust emissions and keep spark plug fouling to a minimum.
This vehicle will perform best with fuel listed in the table.
* U.S. federal law requires that octane ratings be posted on gasoline st ...
Mazda 6 Owners Manual: Head Restraints
Your vehicle is equipped with head restraints on all outboard seats and the rear
center seat. The head restraints are intended to help protect you and the passengers
from neck injury.
WARNING
Always drive with the head restraints installed when seats are being used
and make sure they are pro ...