Why is the battery not charging? Possible reasons

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:41

Owners of used or rather old cars may face such a problem as the lack of efficient battery charging. This is a common situation that occurs for various reasons. Sometimes the battery will not get a charge even when using a special charger, but do not rush to throw it away. First of all, you need to figure out why the battery is not charging and eliminate the reasons.

Problem definition

If the car is not charging the battery, it will be noticeable on the operation of electrical equipment immediately. At a minimum, the car simply will not start, because the starter needs to turn the engine to start the engine, and energy is taken from the battery to spin it up. However, if the car is pushed or rolled down a hill, then the engine will be spun due to the wheels, and so it will also start. This cannot be done with an automatic transmission.

Often battery devicenothing at all, and the problem may be hiding in the generator or even the wires. To determine the malfunction, first of all, you need to check the voltage at the terminals with a multimeter. If you don’t have your own multimeter, then any service station or just a neighbor in the garage has it. Note that if the battery is not charging, we can only find out the main reasons with a multimeter. We just need him.

Checking with a multimeter

To check the engine must first be started. We start, set the voltage measurement mode on the multimeter, connect its probes to the battery terminals. If charging is in progress, the voltage will be in the region of 14-14.4 V. If the battery is not charging, then the voltage on the multimeter will be 12 V or lower if the battery is too low.

If you connect the battery to the charger and measure the voltage with a multimeter, you can see that the voltage at the terminals is constantly increasing, which indicates a full charge. It will stop at a certain value - this is normal. However, if the voltage does not change at all since charging, then it means that charging is not going on at all.

This simple test method allows you to understand whether the problem is in the battery itself or if it should be looked for in the generator. In any case, now you know how to check if the battery is charging. However, this requires a multimeter. Fortunately, this is an inexpensive device that is sold in anyspeci alty store.

Why is the battery not charging? Reasons

One of the most common causes is plate sulphation, which occurs when the battery has not been used for a very long time. During sulfation, a white coating forms on lead plates - these are lead sulfate crystals, which reduce the working surface of the plates. As a result, the battery capacity is greatly reduced. If the battery is operating normally, that is, constantly being discharged and charged, then crystals will not form. They only appear when idle.

If there are few of these crystals on the plates, then you can get rid of them by constantly discharging and recharging the battery. For this, even special chargers are provided that charge the battery, then apply a large load to discharge it, then charge it again, etc. When receiving and releasing a charge, the crystals gradually disappear, the working surface of the lead plates increases, and the battery is able to accept a normal charge. However, this can be done without special charging. But in this case, it will take two or three days to charge and discharge (connect lamps to it, for example) the battery, which is not very convenient.

In cases where sulfation affects large areas of the plates, physical cleaning will be required. That is, the plates themselves are removed from the plastic container (the acid solution is previously drained) and the crystals are removed manually. This is a radical way that often requiressoldering the top cover of the battery. It must be done very carefully, as there is acid inside, and getting it on the skin will cause severe burns.

Such a malfunction occurs only on old batteries. Therefore, if the VAZ-2107 battery is not charging, then the matter is most likely in sulfation. On relatively new batteries, the first step is to check if the terminals are oxidized.

Oxidated terminals

Oxidation is the process of chemical interaction of a metal with oxygen contained in the air. As a result, a white coating forms on the terminals, which significantly increases the resistance. It is logical that with a high resistance, a normal battery charge is not possible, so the plaque must be removed. This can be done with ordinary fine-grained sandpaper. It is worth considering that you need to rub the terminals carefully, because lead is a soft metal. After removing the plaque, the terminals must be fixed back and the charge checked.

Note that this is the most banal and insignificant problem that can be easily solved.

Oxidation or broken wires

Not only the terminals can be oxidized, but also the wires. Or rather, not the wires themselves, but the places where they come into contact with the terminals. They also need to be cleaned with sandpaper and reconnected. In rare cases, the wire may burn out in some place due to a voltage drop. This will cause an open circuit and the battery will not charge, as it will not be connected to the generator at all. Therefore, it is necessary to inspect the entire wire for burnout.

Timing belt slip

The next reason why the battery is not charging may be the timing belt. When starting the engine, this belt keeps it running smoothly. If the belt is badly worn, then it may slip, which will lead to unstable rotation of the engine crankshaft and, as a result, the generator rotor.

Note that belt slippage produces a characteristic high-pitched whistle that comes from under the hood when the engine is running. And a break in this belt can generally bend the valves of the power plant, not to mention the inability to charge the battery. Therefore, it is very important to monitor the suspicious whistle that can be heard from under the hood, as well as change the timing belt in a timely manner. Depending on the model of the car, manufacturers recommend replacing it after 50-80 thousand kilometers. It is advisable to adhere to the frequency, because as a result, bent valves will require large investments in repairs. However, a broken timing belt does not always bend the valve, but this is no longer the topic of this article.

Generator Relay Diodes

The battery charging system, although simple, includes many devices. Failure of any of them can cause the battery to fail. A common item that often fails is the generator relay.

The check is carried out as follows: using a multimeter, the voltage at the battery terminals is measured when theengine. Then the engine is started and the voltage is measured again. Normally, the voltage with the engine running should be 13.5-14.3 V, with the engine not running - 12.5-12.7 V. If you increase the speed while the engine is running by pressing the gas pedal, the generator will spin faster, the value on the multimeter screen may also increase. Nothing like this should happen, but if there is an increase in voltage, then the problem is most likely a malfunction of the generator relay diodes. In this case, the generator is unscrewed, its cover is opened and the relay is completely replaced. A person without experience in such work is unlikely to cope with such a task, so you will have to follow the service station.

After replacing the diodes, the battery will receive normal current. Therefore, it will also charge normally.

Problem with the battery itself

If everything is in order with the generator, then only the battery remains. It has already been written about sulfation above, but the reasons why the VAZ battery and other car brands are not charging may be different.

Alternatively, you can try to replace the electrolyte. To do this, liquid is drained from all cans, distilled water is poured. After some time, this water also needs to be drained and filled with electrolyte - it is sold in almost all stores with goods for cars where there are batteries. After changing the electrolyte, the battery may recover.

By the way, it is very important to keep the electrolyte density at 1.285 g/cm3. Densitymeasured with a special device, which drivers most often do not have. Therefore, it is best to do this operation at the service station.

In general, if something is wrong with the battery, then it is most often simply changed to a new one. The old one is for sale. Usually, when buying a new battery, the old one is taken away for an average of 400-500 rubles. Thus, if the VAZ battery or other car brands are not charging, then the replacement option looks attractive. The battery is a consumable item and has a limited lifespan, so don't get too upset if it fails. This is quite normal when it comes to old appliances.

More reasons

And although there are only three main reasons (the battery, the generator itself, the circuit between these devices), the malfunction may lie deeper. Very old generators have very worn rotors. They can get stuck in the process. If this happens, then a complete replacement of this unit is necessary. An open circuit is also possible, through which the generator is driven. It is quite difficult to determine the specific location of the cliff, and only experienced craftsmen at the service station can do this.

Conclusion

Now you know why the battery is not charging. Unfortunately, this is a common problem, which in most cases is solved by replacing the latter. But this is not the worst malfunction that can happen to any car, so do not get too upset about this.