Pic. 7.4. Mazda 6 car battery: 1 - negative terminal wire; 2 - positive terminal wire; 3 - mounting bracket; 4 - storage battery; 5 - lower tray
The vehicle covered in this manual has a 12V electrical system. The body ground is connected to the negative battery terminal. The battery is located in the engine compartment or under the rear seat (models with air conditioning, as well as some diesel modifications).
The battery performs three main functions in the vehicle's electrical system:
- gives electric current to start the engine;
- stabilizes the voltage in the electrical system;
- can provide current for a short time when the power consumption exceeds the generator output power.
Sealed batteries are standard on all vehicles. They don't have filler plugs. The battery is completely sealed apart from two small side ventilation holes. These vents allow the resulting gases to escape.
Sealed batteries have the following advantages over conventional batteries:
- for the durability of the batteries, you do not need to add water;
- the battery is protected from overcharging. If too much voltage is applied to the battery, it will not take as much current as a normal battery. Increasing the voltage will continue to charge a conventional battery, resulting in gassing and loss of electrolyte;
- The battery can be recharged like a normal battery. This is very important when the car is in one place for a long time;
- with smaller dimensions and weight, the voltage and current remained the same.
The battery has two indicators:
- the battery capacity indicator is determined at 27°C. The capacity when fully charged provides 10.5V or more;
- cold start battery capacity is determined by testing at -18°C. With this test, you can determine the power of the battery when cranking the crankshaft on a cold engine.
Battery backup power is defined as the maximum amount of time possible to drive at night with minimal electrical load without using generator output. Expressed in minutes, standby power (or indicator E) is the time required for a fully charged battery at 27°C and a discharge current of 25 A to reach a voltage of 10.5 V at the terminals.
Battery life is not unlimited. However, with proper care, the battery will last for many years.
If the battery tested well, but malfunctions are detected, the following factors may be the cause of the malfunction or failure:
- some appliance was left on all night;
- for short periods the car was moving at low speed;
- the electrical load of the car exceeded the output power of the generator, often with the inclusion of non-standard equipment;
- malfunction in the charging system - slipping of the generator belt, malfunction of the generator or voltage regulator, etc.;
- improper use of the battery - failure to clean, improperly fasten the terminals or loosen the clamps;
- mechanical malfunctions of the electrical system - shorted or pinched wires.
Sealed batteries have a built-in hydrometer used for diagnostics.
Visible «green dot» means the battery is ready for testing.
Color change «green dot» darker indicates that the battery is not ready for testing. In this case, it is necessary to check the electrical systems and charging.
Light yellow means that the liquid level has dropped below the tip of the hydrometer. This may cause excessive or prolonged charging or deterioration of the battery. If the battery cannot be recharged, replace it.