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: Receiving and Replying to Messages (available only with E-mail/SMS compatible
phones)
SMS (Short Message Service) messages, and E-mail received by connected devices
can be downloaded, displayed, and played (read by the system).
Additionally, replies can also be made to calls and messages in the received
messages.
Downloading messages
Up to 20 new messages can be downloaded and ...
Mazda 6 Owners Manual: Supplier identification procedure
Note
When asking the supplier (service center) for repair or
replacement, verify which supplier the module belongs to and enter in the
Audio Repair Order Form.
Identification With Printed Numbers/Label
1. Remove the audio unit.
2. Verify the supplier name written on the label attached ...