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: Intermittent concern troubleshooting
Vibration Method
1. If malfunction occurs or becomes worse while driving on a rough road or
when engine is vibrating, perform the steps below.
Note
There are several reasons vehicle or engine vibration could cause
an electrical malfunction. Some of the things to check for are:
...
Mazda 6 Owners Manual: Front outer handle removal/installation
1. Remove the front door glass.
2. Detach the outer handle and front door latch rod.
3. For protector-equipped vehicles, refer to key cylinder
removal/installation to remove the protector.
4. Remove the bolts.
5. With the rear side of the outer handle fixed and the outer handle lever
pulle ...