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: Moonroof (Some models)
The moonroof can be opened or closed electrically only when the ignition is switched
ON.
WARNING
Do not let passengers stand up or extend part of the body through the open
moonroof while the vehicle is moving: Extending the head, arms, or other parts
of the body through the moonroof is dan ...
Mazda 6 Owners Manual: Replacing Exterior Light Bulbs
Headlights (With LED headlights)
Low/High beam bulbs
The LED bulb cannot be replaced as a single unit because it is an integrated
unit.
The LED bulb has to be replaced with the unit. We recommend an Authorized Mazda
Dealer when the replacement is necessary.
Headlights (With halogen headlight ...