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: Pid/data monitor inspection
1. Connect the WDS or equivalent to the DLC-2.
2. Measure the PID value.
Note
Perform part inspection for the output device after PCM
inspection.
The PID/DATA MONITOR function monitors the calculated value of the
input/output signals in the PCM. Therefore, if a monitored value ...
Mazda 6 Owners Manual: Closing the Hood
1. Check under the hood area to make certain all filler caps are in place and
all loose items (e.g. tools, oil containers, etc.) have been removed.
2. Lift the hood, grasp the padded area on the support rod, and secure the support
rod in the clip. Verify that the support rod is secured in the c ...