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: If a Warning Light Turns On or Flashes
If any warning light turns on/flashes, take appropriate action for each light.
There is no problem if the light turns off, however if the light does not turn off
or turns on/flashes again, consult an Authorized Mazda Dealer.
The warning contents can be verified on the center display.
1. If the ...
Mazda 6 Owners Manual: Wheel hub, steering knuckle removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-speed sensor (axle side) and fix it to an appropri ...