However, over time (after 3–5 years of operation) the battery starts to gradually lose capacity. This is manifested, first of all, in difficult starting of the engine in cold weather (the starter does not turn the crankshaft or cranks too slowly).
This symptom may indicate that the battery needs to be replaced. But if it is not possible to replace it, but it is necessary to start the engine, you can use the old driver’s method: "lighting up", that is, starting the engine by connecting the battery of another (serviceable) car.
Many drivers often mistake other engine problems for a discharge or battery malfunction (ignition systems, power supply, etc.). A characteristic sign of a battery failure is a quick start of the engine when "lighting up". If the engine does not start immediately, it is useless to continue this procedure, but you should start troubleshooting its other systems. If, after starting the engine from the "donor" car battery and then recharging the discharged battery, the starter again refuses to turn the engine crankshaft, then the battery is faulty and needs to be replaced.
For "lighting" you need a set of two connecting cables, always factory (not homemade!) manufacturing.
Cables must have a conductor cross section (without insulation thickness) not less than 16 mm 2 - this is approximately equal to the cross section of the wire connecting the battery to the starter (also excluding insulation thickness). The length of each cable must be at least 1 m (optimally 1.2–1.5 m).
At the ends of each cable, clamps are factory-installed for fastening to battery terminals. In order not to reverse the polarity when connecting, one of the cables or only the handles of its clamps are colored red. This cable is typically used to connect the "positive" battery terminals. The cable connected to the "negative" terminal of the battery of the "donor" car has a black (rarely - blue) color.
Starting an engine with a faulty battery from the battery of a "donor" car is a simple operation, but at the same time responsible and even dangerous.
Strictly adhere to the described procedure, and if you doubt your abilities, entrust it to more experienced drivers or call a technical assistance car. Mobile service stations often carry out this operation (especially in cold winters) and have professional equipment and instruments for this purpose.
On each car, apply the parking brake and set the gearshift lever to neutral (on a car with an automatic transmission, we move the selector to position P).
On both cars, turn off the ignition and all appliances and devices that have power.
We lift the plastic protective covers from both terminals of the discharged battery and disconnect the wire terminal from the "negative" terminal of the discharged battery (see Removing the battery).
We connect the clamp "positive" (red) connecting cable with the "positive" terminal of the discharged battery...... and the second clip - with the "positive" terminal of the battery of the "donor" car. We connect the clamp "minus" (black or blue) cable with a "negative" battery terminal of the "donor" car. The second clamp of the "negative" cable is connected to the "mass" (body or engine) car with a dead battery at a distance of about 0.3 to 0.5 m from the battery. It is best to connect the clamp of the "negative" cable to massive metal, unpainted and uncontaminated engine parts.
On a car with a 1.6 liter engine, it is convenient to attach the clamp of this cable to the engine eye-bar.
A power surge in the on-board network of a car with an electronic engine management system can disable the electronic engine control unit. That is why it is necessary to start the engine with a discharged battery using connecting cables only in the sequence described above.
We start the engine of the "donor" car. After letting it run for 3–5 minutes at idle, we slightly increase the engine speed, after which the second driver should try to start the car engine with a discharged battery. Usually, one turn on of the starter is enough to start, but it happens that you need to make 2-3 attempts. The duration of continuous operation of the starter at each start should not exceed 6 s. If the engine starts, you should maintain an increased speed of the crankshaft of the car with a discharged battery for some time by pressing the "gas" pedal so that when the battery of the "donor" car is disconnected and the discharged battery is connected, the engine does not stop.
Next, we connect the standard "negative" wire to the "negative" terminal of the discharged battery, and only then disconnect the clamp of the "negative" cable from the "mass" of the car with a discharged battery. This is necessary in order to avoid a sharp power surge in the on-board network of the "donor" car. After that, disconnect the clamps of the "positive" cable from the "positive" output of the discharged battery and the "donor" battery.
When "lighting" it is necessary to take the following precautions: - do not touch the uninsulated sections of the clamps of the connecting cables while they are connected to the terminals of the batteries; - when connecting the "positive" terminals of the batteries with a red cable, make sure that the uninsulated sections of the clamps do not come into contact with the metal parts of the car that have contact with the "ground", this can cause a short circuit and damage to the battery; — at an ambient temperature of –10°C or lower, the electrolyte of a discharged battery freezes. When "lighting up" a battery with frozen electrolyte, an explosion may occur. To avoid an explosion, you must first warm the battery in a warm room; - do not connect the connecting "negative" cable directly to the "negative" terminal of a discharged battery due to the risk of ignition from an accidental spark and explosion of explosive gas released during charging.