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: Advanced Keyless Entry System
WARNING
Radio waves from the key may affect medical devices such as pacemakers:
Before using the key near people who use medical devices, ask the medical device
manufacturer or your physician if radio waves from the key will affect the device.
The advanced keyless function allows you to lock/u ...
Mazda 6 Owners Manual: Rear window glass removal
1. For the 4SD, remove the following parts:
(1) Remove the headliner.
(2) Remove the rear package trim.
2. For the 5HB, remove the following parts.
(1) Remove the rear wiper arm and blade.
(2) Remove the liftgate lower trim.
3. Apply protective tape along the edge of the body to pr ...