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: Fuel Gauge
The fuel gauge shows approximately how much fuel is remaining in the tank when
the ignition is switched ON. We recommend keeping the tank over 1/4 full.
If the fuel level is low, and
turn an amber color. Refuel as soon as possible.
Refer to Taking Action.
NOTE
After refueling, it m ...
Mazda 6 Owners Manual: Fuel injector inspection
Operation Test
Carry out the Fuel Injector Operation Inspection. (See Fuel Injector
Operation Inspection.)
If not as specified, perform the further inspection for the fuel
injectors.
Resistance Inspection
Note
Perform the following test only when directed.
1. Turn the ignition s ...