Power pack: Maintenance-free battery
Six cells connected in series are the heart of a 12-volt starter battery. Each cell consists of a combination of positive and negative plates, which chemically produces a voltage of about two volts. The plates, in turn, consist of grids made of lead-antimony alloy, which are filled with an active mass. On the sides of the positive plate is lead peroxide, the reagent of the negative plates is pure lead. Between them is a separator - it separates the plates from each other, but the battery fluid (electrolyte) can circulate through the microscopic pores. The electrolyte is a conductive liquid, which is almost 37% concentrated sulfuric acid and 67% distilled water.
Stores electrical energy - battery
Energy processes take place in the protected "insides" of the battery - chemical energy is converted into electrical energy in the battery. The main consumer of "power juice" is the starter. Its traction force depends on the accumulated energy that the battery produces and stores during movement: depending on the type of starter motor, the starter "sucks" up to 2000 watts for a short time - for this, the battery must be in good "physical" shape.
At each cold start, the greater part of the immense power goes to the account of internal friction losses. On the contrary, the starter realizes the start of a heated engine with the help of a fifth of the power necessary for starting a cold engine. All swinging and rotating parts interact better with each other due to the greater "space", and "warm" oil is more flexible than cooled oil, which at first circulates extremely discontentedly in the circulation system.
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TECHNICAL DICTIONARY |
Battery - concepts and standards
The designation is located on the case and characterizes the parameters of the battery. For example, "12V 70 Ah 210A" (12V (B) = nominal voltage; 70Ah (A h) = nominal capacity; 210A = starter discharge current.
Nominal voltage: Total voltage output (dimension "V"). All Mondeo models are set to 12 V. The actual voltage depends, of course, on the degree of discharge of the battery. It can be higher or lower than the nominal value.
Nominal capacity: Determines the storage capacity of the battery (dimension "A h"). This is the capacity that a fully charged battery can have at a temperature of 27°C for 20 hours, and in this case the voltage of the cell will not fall below 10.5 V (the final discharge voltage). The parking light of your car, for example, consumes 25 watts. With an on-board network voltage of 12 volts, the battery produces a current of 2.08 A, according to the formula "current (A) = power (W) / voltage (V)". With a battery of 70 Ah, theoretically your Mondeo can be driven with the parking light on for about 30 hours. The emphasis here is on the word "theoretically", since in practice the battery will be completely discharged and powerless after about 10-15 hours.
Capacity: The current consumption of the battery in ampere-hours (A h). It depends primarily on the discharge current, temperature, degree of discharge and general condition (aging) of the battery.
Cold cranking current: Determines the ability of the battery to start in cold weather (dimension "A"). A certain discharge current that a 12-volt battery can produce at a temperature of -18°C. In this case, the voltage will not fall below 9 volts for 30 seconds, and 6 volts for 150 seconds, respectively.
Self-discharge: Chemical processes occurring inside the battery cells cause it to discharge – even if no current consumer is connected. A charged, almost new car battery loses about 0.5% of its charge daily. Strong temperature fluctuations, damage or a dirty battery case also accelerate the discharge process. Starter with forced switching on and self-switching off with a gearbox
When starting, the starter with forced engagement and self-disengagement breathes the necessary "life force" into the Mondeo. - Turn the ignition key to the "Start" direction, current flows through the ignition switch (terminal 50) to the electromagnetic switch located above the starter.
- It sets the engagement fork in motion: it then moves the starter gear along the steep thread of the armature shaft into the toothed rim of the engine flywheel (pushing stroke).
- At the end of the pushing stroke, the starter pinion is "installed" directly in front of the flywheel – this is a signal for the electromagnetic switch via its main contacts to "open the way" to the full current of the battery (terminal 30). The pinion is then screwed into the toothed rim and thus creates a force closure (screwing stroke) – the starter turns the engine.
- As soon as the engine shows its first "signs of life" and you release the ignition key, the electromagnetic field in the holding winding of the electromagnetic switch disappears - a starting signal for the return spring to return the starter fork to its original position. The starter gear disengages from the flywheel, the starter itself is already de-energized.
Starter with forced switching on and self-switching off and gearbox. |
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