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: Headlight aiming
Low-beam
1. Set up a screen as shown in the figure below for aiming the headlights.
2. Adjust the tire air pressure to the specification.
3. Position the unloaded vehicle on a flat, level surface.
4. Seat one person in the driver's seat.
5. Position the vehicle straight ahead and perpendicu ...
Mazda 6 Owners Manual: Theft-deterrent control module inspection
1. Remove the theft-deterrent control module without disconnecting the
connectors.
2. Measure the voltage at the theft-deterrent control module terminals as
indicated below.
3. Disconnect the theft-deterrent control module connector before inspecting
for continuity at terminals L, Q, S, T, a ...