We check devices that retain battery charge during long-term parking. Eight samples are being tested.

Many people are not even aware of the existence of such devices. Everyone knows about chargers, but what are they? And in what cases may they be needed?

We will return to the terminology later, but these “recharges” are needed for this reason. Imagine a car sitting in a garage for weeks without moving. When you suddenly need it urgently, it turns out that the battery is so low that it cannot turn the starter. What if this happens all the time?

Cars that are on exhibition stands often find themselves in a similar situation. Their audio system is playing, the lights are on, but the engine is not running. So thin wires stretch under the hood, feeding the standard battery of the car from an external source.

Large currents are not needed: it is enough to compensate for the consumption of standard microcontrollers, as well as security system and telematics. Modern gadgets have a modest appetite - tens of milliamps, despite the fact that their analogues from previous years of production sometimes consumed an order of magnitude more.

It would seem that connect charger- and no problem! But not every “charge” is designed for continuous operation for weeks, or even months. It’s another matter if the manufacturer indicates a similar possibility of using their product. These are the devices we decided to test in real conditions - for several months.

Of the eight purchased products, only two are pure “recharges” - Tornado and Moratti. The rest are “chargers” that promise not only to revive dead batteries, but also to maintain their charge at the proper level. It was this function that we evaluated during the tests.

WHAT WE TESTED AND WHERE

The tests were carried out in the laboratory of the Federal State Institution 3 Central Research Institute of the Ministry of Defense of the Russian Federation for three months. A long-term test of the devices’ ability to compensate for a drop in charge was carried out on batteries with an energy capacity of 55, 75 and 90 Ah at temperatures of -20; 0; +25 ºС. The tendency to overheat was assessed when working with batteries from 75 to 190 Ah, setting the maximum possible load for each device. For each product, they checked the “fool resistance” - they used polarity reversal, etc. When arranging in places, they took into account the declared parameters, workmanship, correctness of instructions and ease of use.

They decided to open the Tornado device in a “foreign” case. It's well put together, but it's at the level of the last millennium. Dates on radio elements reveal themselves.

STORAGE? RECHARGING? COMPENSATION?

The multi-month marathon ended successfully: not a single device asked for mercy, not a single battery complained of poor service. “Fool protection” is also at its best: the products are not afraid of polarity reversals and other provocations. At the same time, not everyone liked it - we spoke about this topic in detail in the captions of the photo gallery. We also note that all devices provide recharging in 20-degree frost - even those that, judging by the instructions, are not at all frost-resistant.

But you need to be more polite with wires - they lose their flexibility right before your eyes.

Is it worth looking for simple chargers in stores, or is it better to buy a multifunctional charger? We believe that the second option is preferable: the difference in price is not cosmic, and a full-fledged charger in the household will not hurt. In addition, they are almost always on sale, and exotic “smaller brothers” need to be looked for via the Internet.

8. STARTED AZU-108 8 7 6

Automatic pulse charger, Saint Petersburg

Approximate price, rub. 1280

Temperature range, ºС 0…+40

3–110

The cute device was unpleasantly jarring to the eyes with the illiterate “A/h” inscriptions on the front panel, in the instructions and on the packaging. There is no such unit of measurement in nature - there is Ah. The manufacturer's requirements for the temperature conditions of the device's operation - from 0 to 40 ºС - were not encouraging: how to maintain the battery charge if it is frosty outside? The execution is sloppy: the glued switches are loose. In general, the device is functional, but I don’t want to recommend it.

7. Tornado 3 A.02

Automatic charger for batteries, Tolyatti

Approximate price, rub. 860

Temperature range, ºС -20…+40

Energy capacity of rechargeable batteries, Ah up to 75

The device promises to maintain the working condition of the battery “for as long as desired”, without being a full-fledged charger (except for batteries with an energy capacity below 10 Ah). Outwardly, it resembles an amateur radio design in a housing from a time relay for photo printing. The element base is a quarter of a century old. The product successfully passed all electrical tests (overheating tests were carried out with a 75 Ah battery). However general impression rather negative.

6. Moratti 01.80.005

Battery recharger, China

Approximate price, rub. 600

Temperature range, ºС not lower than -10

Energy capacity of rechargeable batteries, Ah 10–250

The device is not intended for charging batteries, but to maintain battery performance during long-term storage and infrequent use. Withstands long-term operation calmly; The overheating test was carried out on a battery with an energy capacity of 190 Ah. There are no comments about the technology, but I didn’t like the description: what are “gel” batteries? Maybe they meant gel ones?

5. SONAR U3 207.03 3

Charger, Saint Petersburg

Approximate price, rub. 1500

Temperature range, ºС -5…+35

Energy capacity of rechargeable batteries, Ah 10–180

The charger provides storage mode with self-discharge current compensation. Unfortunately, the lower temperature limit is only -5 ºС. In other words, the device is not designed for winter operation in an unheated garage. The case does not overheat during operation (the test was carried out with a battery with an energy capacity of 170 Ah). There are no complaints about the technology, but the price seemed overpriced.

4. AIRLINE ASN‑5 A‑06

Charger, Russia - China

Approximate price, rub. 1050

Temperature range, ºС no data

Energy capacity of rechargeable batteries, Ah up to 65

Provides a charging mode for the battery installed on the vehicle. The overheating test was carried out on a battery with an energy capacity of 65 Ah; no reasons for comment were found. It copes with recharging successfully. Unfortunately, the mythical unit of measurement A/h is found in the description of this device...

3. HEYNER, AkkuEnergy Art. 927130

Charger, Germany

Approximate price, rub. 6000

Temperature range, ºС no data

Energy capacity of rechargeable batteries, Ah 30–190

A charger designed for long-term connection to the battery, regardless of the season. All tasks were completed without problems. The overheating test was carried out with a 190 Ah battery. Among the shortcomings are an abstruse description with poor translation and an unappetizing price.

1–2. SMART POWER SP‑2N BERKUT

Compact universal charger, Russia - China

Approximate price, rub. 1150

Temperature range, ºС -20…+50

Energy capacity of rechargeable batteries, Ah 4–80

It can also be used for seasonal battery storage, remaining connected to the network for several months. The long-term operation mode is tolerated calmly; The overheating test was carried out with a 90 Ah battery. “Fool resistance” is normal, there are no comments on the work.

1–2. SOROKIN® 12.98

Universal battery charger, Russia

Approximate price, rub. 3000

Temperature range, ºС -20…+50

Energy capacity of rechargeable batteries, Ah 6–160

Full charger. Can be connected to a car battery for a long time - for winter storage and year-round use. It does not overheat during operation (the test was carried out with a 170 Ah battery). No comments. It's just a little expensive.

A LITTLE ABOUT SAFETY

If you leave a charger connected to the mains in the garage for a long time, make sure that you have not cheated. In other words, you must be sure that the “crocodiles” connected to the terminals of the engine compartment battery will not give you a short circuit under any circumstances (for example, when touching the hood when it is being closed!), and the corresponding wires will not be pinched by the hood cover or in any other way. Yes, the devices we tested have built-in protection, but don’t hesitate to double-check yourself. It goes without saying that the charger must be guaranteed to be protected from direct contact with moisture, snow and other weather hazards. It should also be remembered that at low temperatures, wire insulation has a habit of hardening and even breaking. This is especially important to take into account in cases where the car is used from time to time, and the charger is in a hurry either disconnected or reconnected, without paying attention to such “little things”.

What damage to the insulation of the positive wire can cause if it accidentally touches ground is clear to everyone.

And one last thing. Before moving away, do not forget to disconnect the charger from the mains and from the battery.

Currently, there are many methods for charging batteries. There are more modern ones that require special chargers, and there are also simple, classic charging methods that have been known since the creation of rechargeable batteries and are popular to this day.

Today we will look at two classic methods of charging a battery.

1. Battery charge at constant charging current. I=const.

2. Charge the battery at constant charging voltage. U=const.

Today we will need the following devices:

1. Level tube (if available)

2. Hydrometer.

3. Voltmeter (multimeter or built-in charger).

4. Charger.

Before you start charging the battery, you need to make sure that this is necessary, that is, check the battery and prepare it for charging, for this we need:

1. Clean the battery case and terminals from oxides, remove the filler plugs

2. Check the electrolyte level using a level tube and if a low level is observed (less than 10-12 mm), it is necessary to add distilled water.

3. Measure the density of the electrolyte using a hydrometer

4. Measure the voltage (emf) of the battery using a voltmeter or multimeter.

And it is advisable to write down or remember these values; we will need them to monitor the end of the battery charge.

Based on the measured density and voltage values ​​of the battery, assess whether it still needs charging or not.

The density of the electrolyte in a fully charged battery measured at a temperature of +25°C, depending on the climate zone, should correspond to the values ​​​​indicated in the table.

The voltage on a fully charged battery must be at least 12.6 volts.

Do not charge the battery unless necessary, as this will shorten its service life by overcharging the battery.

The principle of battery charging is that voltage from the charger is connected to the battery, and for the charging current to occur, that is, to begin the battery charging process, the charging voltage must always be more battery voltage.

If the charging voltage is less than the voltage on the battery, the direction of the current in the circuit will change and the battery will begin to give up its energy to the charger, that is, discharge to it.

So, let's look at the first method of charging a battery.

Charging the battery at a constant charging current.

Charging a battery with a constant charging current is the main universal charging method. You need to know that when using this method, unlike some others, the battery is charged to 100% of its capacity.

With this method, the charging current is maintained constant throughout the entire charge.

This is achieved either by using special chargers with the function of setting a given value of the charging current, or by including a rheostat in the charging circuit, however, in the latter case, you must change the resistance values ​​of the rheostat yourself to achieve a constant charging current during the charging process.

The point is that during the charging process, the battery resistance and voltage on it change, which leads to a decrease in the charging current. To maintain the charging current at a constant level, it is necessary to increase the value of the charging voltage using the above-mentioned rheostat.

I will say again that in modern chargers the charging current value can be maintained automatically.

The charging current is usually selected equal to 10% of the battery capacity, which is indicated on the battery case. In the literature, this capacity is designated as C20, which is the capacity at a 20-hour discharge mode. Just remember this.

The charging time of the battery depends on the degree of its discharge before charging. If the battery was completely discharged but not below 10 volts, then the approximate charging time will be within 10 hours.

If you are not limited by charging time, then it is better to charge the battery with a current of 5% of the battery capacity, while the charging process occurs more efficiently and the battery is charged to 100% of its capacity, while the charging time increases.

The battery is charged until abundant gas evolution, constant voltage and electrolyte density are achieved for 2 hours.

The voltage of the charger connected to the battery usually reaches 16-16.2 volts at the end of the charge.

It should be said that at the end of charging the battery using the constant charging current method, there is a significant increase in the temperature of the electrolyte in it. Therefore, when the temperature reaches 45 degrees, you should reduce the charging current by 2 times, or interrupt the charge altogether to reduce the temperature to 30-35 degrees.

So, we take the charger, connect the positive and negative clamps to the battery terminals, set the charging current setting knob to minimum, that is, to the far left position, and connect the charger to the network.

Next, we set the charging current equal to 10% of the battery capacity and every 2 hours we control the density of the electrolyte, the voltage on the battery, which will increase during the charging of the battery and, if possible, the temperature of the electrolyte, or at least indirectly, by touching the battery case with your hand.

If the charger does not have the function of maintaining a constant charging current, then we maintain it manually by changing the charging voltage and monitoring the charging current every half hour using the ammeter of the charger, or an ammeter connected in series to the charging circuit.

When the voltage reaches approximately 14 volts, we monitor the density and voltage every hour.

If you observe signs of charging (boiling, constant density and voltage), disconnect the charger from the network and disconnect the clamps from the battery.

Our battery is charged.

Disadvantages of the charging method:

1. Long battery charging time (when charging with a current of 10% of the capacity, about 10 hours, when charging with a current of 5% of the capacity - about 20 hours, provided that the battery was completely discharged).

2. The need for frequent monitoring of the charging process (charging current, voltage, density and temperature of the electrolyte).

3. There is a possibility of battery overcharging.

Charging the battery at a constant charging voltage.

Charging the battery while maintaining a constant voltage across it is a faster and simpler method of putting the battery into operation.

The essence of this charging method is as follows.

The charger is directly connected to the battery and maintains a constant charging voltage throughout the entire charging process. In this case, the voltage is set within 14.4-15 volts (for a 12-volt battery).

With this charging method, the value of the charging current is set, one might say, automatically, depending on the degree of discharge, electrolyte density, temperature and other factors.

At the beginning of battery charging, the charging current can reach large values, even 100% of the battery capacity, since the emf of the batteries has the smallest value, and the difference between this emf and the charge voltage is the greatest. However, during the charging process, the battery EMF increases, the difference between the battery EMF and the charging voltage decreases, thereby reducing the charging current, which after 2-4 hours can reach about 5-10% of the battery capacity. Again, it all depends on the degree of discharge of the battery.

Such high charge currents are the reason for faster charging of batteries.

At the end of the battery charging process, the charging current decreases to almost zero, so it is believed that when charging by maintaining a constant charging voltage, the battery will only charge to 90-95% of its capacity.

Thus, when the charging current is close to zero, the charge can be stopped, the battery can be restored to its original state and installed on the car.

By the way, the battery is charged at a constant charging voltage in a car.

If the battery voltage is less than 12.6-12.7 volts (depending on the car brand), then the regulator relay connects the generator to the battery to recharge it. Moreover, the voltage from the generator corresponds to a value of 13.8-14.4 volts (standard value; in foreign cars the generator voltage is found to be slightly higher than the specified value).

1. Connect the charger to the battery,

2. Set the charging voltage within 14.4-15 volts,

3. Control the battery charging current

4. Remove the battery from charging when the current value is close to zero.

Disadvantages of the method:

1. The battery is not charged to its full capacity, but on average to 90-95% of its value.

2. Large overload of the charging voltage source at the beginning of the charge, due to a large charging current (relevant when charging the battery from a car generator).

After charging the battery using any of the methods, you must:

1. Make sure that the voltage on it is at least 12.6 volts,

2. Electrolyte density within 1.27 g/cm3

3. Electrolyte level 10-12 mm above the plates

4. Eliminate possible electrolyte leaks and install the battery on the car.

And now the question. In some videos on YouTube and in articles on websites, I came across the following advice on connecting the charger to the battery: first connect the plus, then the minus. So I would like to know your opinion: is this statement correct or does the sequence of connecting the charger wires not matter?

Write your opinions in the comments.

I suggest you look detailed video in which I explain how to charge a battery using two classic charging methods:

Drip charging

Despite popular belief, trickle charging does not in any way contribute to long-lasting battery life. With this charging method, the current does not turn off even after the battery is fully charged. For this reason, the current is chosen to be small. Even if all the energy transferred to the battery is converted into heat, at low current the battery will not be able to heat up enough. For Ni-MH batteries, which react more negatively to overcharging than Ni-Cd, it is recommended to set the charge current to a maximum of 0.05C. To charge a larger capacity battery, the trickle charging current should be set higher. It follows that low-capacity batteries cannot be charged in devices designed to charge high-capacity batteries due to the danger of excessive heat and reduced battery life. If you place a high-capacity battery in a small-capacity battery charger, it may not be fully charged. Being in such conditions for a long time, the batteries begin to lose capacity.

Unfortunately, it is impossible to reliably determine the end of a drip charge. At low charging currents, the voltage profile is flat and the characteristic maximum at the end of charging is practically not achieved. The temperature rises smoothly and the only method is to limit the charging time. But to use this method, it is necessary, in addition to the exact capacity of the battery, to know the amount of its initial charge. The only way to eliminate the influence of the initial charge is to completely discharge the battery immediately before charging it. And this increases the duration of the charging process and shortens the battery life, which depends on the number of charge-discharge cycles. The next problem when calculating the drop charging time is the rather low efficiency of this process. The efficiency of trickle charging does not exceed 75% and depends on a large number of factors (battery temperature, its condition, etc.). The only advantage of drip charging is the ease of implementation of the process (without monitoring the end of charging). Only recently have battery manufacturers noted that trickle charging has ceased to reduce the capacity of modern Ni-MH batteries.

Fast charging

Most manufacturers of Ni-MH batteries indicate the characteristics of their batteries in the case of fast charging with 1C current. There are recommendations not to exceed 0.75C. The smart charger itself must evaluate the conditions and, if necessary, switch to fast charging. Fast charge is used only at temperatures from 0 to +40°C and with a voltage from 0.8 to 1.8V. The efficiency of fast charging is about 90%, so the battery practically does not heat up. But at the end of charging, the efficiency decreases sharply and almost all the energy supplied to the battery turns into heat. Thus, there is a sharp increase in battery temperature and internal pressure. It causes an opening ventilation holes and loss of part of the battery contents. In addition, under the influence of high temperature, the internal structure of the electrodes changes. Therefore, it is important to stop fast battery charging on time. Fortunately, there are fairly reliable indicators that a charger is capable of doing this.

The operation of the fast charger consists of the following phases:

1. Determining the presence of a battery.
2. Battery qualification.
3. Pre-charge (pre-charge).
4. Transition to fast charging (ramp).
5. Fast charging.
6. Top-off charge.
7. Maintenance charge.

Battery detection phase

At this stage, the voltage at the battery terminals is usually checked. If the voltage is higher than 1.8V, this means that the battery is not connected to the charger or is damaged. If a lower voltage is detected, then the battery is connected and you can proceed to charging.

In all phases, along with the main actions, the presence of the battery is checked. This is because the battery may not be in the charger. If this happens, the charger from any phase should move to checking the presence of the battery.

Battery qualification phase

Charging the battery begins with its qualification phase. This phase is needed for a preliminary assessment of the initial battery charge. When the battery voltage is less than 0.8V, fast charging cannot be performed, an additional pre-charging phase is required. If the voltage is greater than 0.8V, the pre-charging phase is skipped. In practice, it has been observed that batteries do not discharge below 1.0V, and the pre-charging phase is almost never used.

Pre-charge phase

Designed for initial charging of seriously discharged batteries. The pre-charge current value must be selected from 0.1C to 0.3C. Pre-charging must be limited in time. A long pre-charging phase is not required, since the voltage of a working battery should quickly reach 0.8V. If the voltage does not increase, this means that the battery is damaged and the charging process must be interrupted.

During long charging phases, it is necessary to monitor the battery temperature and stop charging when the temperature reaches a critical value. For Ni-MH batteries, the maximum permissible temperature is 50°C. Also, as in other phases, you should check the presence of the battery.

Transition phase to fast charging

When the battery voltage reaches 0.8V, you can proceed to fast charging. It is not recommended to immediately use high charging current. It is not recommended to turn on high current at the beginning of charging. It is necessary to gradually increase the current over 2-4 minutes until the specified fast charging current is reached.

Fast charge phase

The charging current is set from 0.5-1.0C. In this phase, it is important to accurately determine the moment of its end. If the fast charging phase is not stopped in time, the battery will be destroyed. Therefore, to determine the exact end time of fast charging, it is necessary to use several independent criteria.

For Ni-Cd batteries, the –dV method is usually used. During charging, the voltage increases, and at the end of charging it begins to decrease. For Ni-Cd batteries a sign of the end of charging is a decrease in voltage by approximately 30 mV (for each battery). The –dV method is the fastest and works great even for not fully charged batteries. If you use this method to start charging a fully charged battery, the voltage on it will quickly increase and then decrease sharply, which will cause the end of the charging process.

For Ni-MH batteries, the method does not work as successfully, since the decrease in voltage for them is less noticeable. At charging currents less than 0.5C, the maximum voltage is usually not reached, so a charger for small-capacity batteries often cannot correctly detect the end of charging for large-capacity batteries.

Due to the slight drop in voltage at the end of charging, it is necessary to increase the sensitivity, which can lead to early termination of fast charging due to noise generated by the charger and also penetrated from the mains supply. That is why you should not charge batteries in a car, due to the fact that the on-board network, as a rule, has too high level interference The battery is also a source of noise. For this reason, filtering should be used when measuring voltage. Therefore, filtering must be used in the voltage measurement process.

When charging batteries of series-connected batteries, when individual batteries differ in the state of charge, the reliability of the –dV method is noticeably reduced. In this case, the voltage peak different batteries is achieved at different times, and the voltage profile is blurred.

For Ni-MH batteries, the dV=0 method is also used, in which, instead of a voltage decrease, a plateau in the voltage profile is detected. In this case, the end of charging is indicated by constant voltage on battery for several minutes.

Despite all the difficulties in determining the end of battery charging using the –dV method, most manufacturers of Ni-MH batteries define this method as the main one for fast charging. At the end of charging with a current of 1C, the voltage should change from -12mV to -2.5mV.

Immediately after connecting a large charging current, the voltage may experience fluctuations, which can be identified as a decrease in voltage at the end of charging. To prevent false termination of the fast charging process, the –dV control must be disabled for the first time (usually 3-10 minutes) after connecting the charging current.

Along with a decrease in voltage at the end of charging, an increase in temperature and pressure inside the battery begins. Thus, the charging completion time can be determined by the temperature rise. However, due to environmental influences, it is not recommended to set an absolute temperature threshold to determine when charging is completed. More often, it is not the temperature itself that is used, but the rate of its change. With a charging current of 1C, charging must be completed when the rate of temperature rise reaches 1°C/min. It should be noted that at charging currents less than 0.5C, the rate of temperature increase practically does not change and this criterion cannot be used.

Both methods discussed cause a slight overcharge of the battery, which leads to a decrease in its service life. To ensure the battery is fully charged, completion of the charging process should be carried out using a low current and at a low battery temperature (at elevated temperatures, the battery's ability to accept a charge is seriously reduced). Therefore, it is recommended to complete the fast charging phase a little earlier.

There is a so-called inflexion method for determining the end time of fast charging. The essence of the method is that the maximum derivative of voltage with respect to time is analyzed. Fast charging stops when the voltage rise rate reaches its maximum value. This method makes it possible to complete the fast charging phase before the temperature has time to rise significantly. This method requires high precision voltage measurements and mathematical calculations.

Some chargers use pulse charging current. Current pulses have a duration of about 1 s, and the interval between pulses is about 20-30 ms. Among the advantages of this method are better equalization of the concentration of active substances throughout the entire volume and a lower probability of the appearance of crystalline formations on the electrodes. There is no exact information about the effectiveness of this method, but it is known that it does not cause harm.

In the process of determining the end of fast charging of the battery, it is necessary to accurately measure the voltage. If these measurements are made under current, then an additional error will appear due to the contact resistance. For this reason, the charging current is turned off during the measurement. After turning off the current, you should pause for 5-10 ms while the voltage on the battery is established. Next, the measurement is carried out. For high-quality filtering of network frequency interference, as a rule, a number of successive samples are taken over an interval of one period of the network frequency (20 ms), and then digital filtering is performed.

Another pulsed current charging method has been developed, called FLEX negative pulse charging or Reflex Charging. It differs from a conventional pulse charge by the presence of discharge current pulses in the intervals between charging current pulses. For charging current pulses of the order of 1 s, the duration of the discharge current pulses is selected to be approximately 5 ms. The magnitude of the discharge current exceeds the charging current by 1-2.5 times.

Among the advantages of the method, mention should be made of a lower battery temperature during charging and the ability to eliminate large crystalline formations on the electrodes. General Electric Corporation has conducted independent studies of this method, which indicate that the method brings neither benefit nor harm.

Since correct detection of the end of fast charge is extremely important, the charger must use several methods to determine the end of charge at once. Also, it is necessary to check some additional conditions for fast charging abort. During fast charging, you should monitor the battery temperature and interrupt the process if it reaches a critical value. For fast charging, the temperature limit is more stringent than for the entire charging process. Therefore, when the temperature reaches +45°C, it is necessary to emergency stop fast charging and proceed to the recharging phase with a lower charging current. Before continuing charging, the battery temperature must decrease, since at elevated temperatures the battery's ability to accept a charge is significantly reduced.

Another additional condition is a time limit on fast charging. Knowing the charging current, battery capacity and charging efficiency, you can calculate the time required for a full charge. The fast charging timer should be set for a time exceeding the calculated time by 5-10%. If this charging time has ended, but none of the methods for determining the end of fast charging has worked, then the process is terminated abnormally. This situation most likely indicates a malfunction of the voltage and temperature measurement channels.

Recharging phase

The charging current is set within 0.1-0.3C. With a recharging current of 0.1C, manufacturers recommend recharging within 30 minutes. Carrying out longer recharging results in overcharging the battery; The battery capacity increases by 5-6%, but the number of charge-discharge cycles is reduced by 10-20%. A positive effect of the recharging process is to equalize the battery charge. Those that are fully charged dissipate the input energy as heat at the same time as the remaining batteries are charged. If the recharging phase follows immediately after the fast charging phase, the batteries must be allowed to cool for a few minutes. As the temperature of the battery rises, its ability to accept a charge drops significantly. At 45°C the battery can only accept 75% charge. Therefore, the recharging process, carried out at room temperature, makes it possible to fully charge the battery.

Float charge phase

Chargers for Ni-Cd batteries after the charging process, as a rule, switch to trickle charging mode in order to maintain the battery in a fully charged state. Thus, the battery temperature remains elevated all the time, and this significantly reduces the battery life. Ni-MH batteries do not tolerate overcharging well, and therefore it is not advisable for them to be in a trickle charge state. It is necessary to use very low current maintenance charging, in order to only compensate for self-charging.

For Ni-MH batteries, self-discharge in the first 24 hours can be up to 15% of the battery capacity, and then self-discharge decreases and amounts to 10-15% of the battery capacity per month. To compensate for self-discharge, an average current of less than 0.005C is sufficient. Some devices turn on the maintenance charging current once every few hours, and at other times the battery is disconnected from the device. The amount of self-discharge depends heavily on temperature, so the best option is to make the float charge adaptive - so that a small charging current is connected only when a specified decrease in voltage is detected.

The maintenance charging phase can be omitted, but if a long time elapses between charging and using the battery, the battery must be recharged before use in order to compensate for self-discharge. The best option is one in which the charger keeps the batteries fully charged.

Ultra-fast charge

When charging up to 70% of the battery capacity, the efficiency of the charging process is close to 100%. This indicator is a prerequisite for the creation of ultra-fast chargers. Of course, it is impossible to increase the charge current indefinitely. There is a limit due to the speed at which chemical reactions occur. In practice, charging currents of up to 10C can be used. To prevent the battery from overheating, after reaching the 70% charge level, the current must be reduced to the level of standard fast charging and the end of charging must be monitored in the standard way. It is necessary to accurately monitor the achievement of the 70% charge mark. There are no reliable methods for solving this problem yet. The problem lies in determining the state of charge in the battery, in which batteries can be discharged differently. It is also problematic to supply charging current to the batteries. With such high charging currents, a weak contact can cause additional heating of the battery, leading to its destruction. If the charger fails, the battery may even explode.

Lead acid batteries used in sources uninterruptible power supply Information storage devices are subject to rapid wear and premature failure during operation. The reason is crystallization of the plates, interelectrode short circuits by dendroid deposits on the surface of the plates, and sulfation.

The capacity and service life of rechargeable batteries depends on the operating mode of the charger and charging method.

Before considering the desired battery charging mode, you should trace the process of battery discharge and the reasons for its premature failure.

As a rule, battery discharge in uninterruptible power systems during operation occurs very rarely and for a period of several minutes, sufficient to take the data storage system out of operation to eliminate the failure. In computer hard drives, during this time the read head will return to its original state, otherwise the boot sectors and working information may be damaged. Subsequently, the lost information can be partially restored, but full use of the hard drive will be impossible.

The lack of discharge characteristics in the battery operation leads to its premature failure.

Batteries in uninterruptible systems are diagnosed by an internal circuit to ensure that the voltage on the battery matches the specified parameters; if there is mains voltage, the uninterruptible power supply device automatically transfers power to the load from the mains. If the mains power is lost, the device must switch to the mode of converting battery energy into a voltage similar in parameters to the mains power supply.

External diagnostics of an uninterruptible power supply battery after operation confirms the presence of high internal resistance - due to high crystallization, high self-discharge when the plates are internally shorted, caused by sulfation. High voltage on the electrodes is diagnosed by the internal circuit as a full charge and the battery is no longer charged. Increasing the charge voltage leads to increased heat generation. The decrease in battery capacity is caused by non-working sulfation of the surface of the plates, the load current is not able to exit the internal layers of the porous structure of the battery plates and the output voltage drops unacceptably under load, leading to a malfunction of the uninterruptible power supply.

A small energy consumption when removing information storage systems from the operating state does not require the installation of powerful car batteries, but powerful chargers to replenish the used battery energy.

To charge the battery and keep it in working condition, you should use a charger using two charging methods: fast charge and trickle (compensation) charge.

The slow charge method used when charging cell phone batteries is unacceptable in this situation, as in cell phones it causes the plates to crystallize and the battery to fail at an unexpected moment.

With this method, the battery does not charge completely or overheats, with thermal destruction of the plates. Data storage systems are operated for more than a day and the batteries in voltage maintenance devices must be in standby charging mode for a long time.

One of the reasons for battery failure is constant current charging in the absence of a small discharge current and lack of cycling in the charging mode. During the discharge current, lead ions have time to be reduced to an amorphous state and deposited on the surface of the plates. During breaks in the charging current pulses, the battery temperature decreases.

The charge of closed type batteries with helium filler must correspond to the following parameters: limiting the charge voltage in order to eliminate overcharging and heating, automatic limitation of the charging current in the initial period of fast charging - this will protect the current regulator from overload and overheating, and the battery cells from an unacceptable amount of charging current, the implementation of jet charging with a pulsed current of short duration and amplitude below the manufacturer's recommended charging current. The average value of the charging current does not exceed 0.05 C, where C is the battery capacity.

Using current cycling to regenerate the plates will keep the battery in working condition for as long as desired. In a short time, the internal resistance of the battery decreases tenfold, and the capacity and operating voltage are restored.

Fast charge mode is characterized by the following parameters:
The charging time is 1-2 hours, this is enough to restore the battery capacity after an emergency switching on of an uninterruptible power supply, the charging current is 0.2-0.3 C, the battery charge level is 100%. The charge does not completely turn off - it switches when the end-of-charge voltage is reached into the buffer jet charging mode. The final voltage of the battery is indicated in the passport or on the case, for example, for a Champion 12 Volt 7 A/h battery installed in an APC type uninterruptible power supply device, it is 13.3 -13.8 V at 20 degrees case temperature. The charging current characteristic is steeply falling - with increasing voltage on the battery, the charging current drops approaching the minimum value of 0.03 -0.05 C - jet charging mode. In the absence of power outages, the battery can remain in a charged state for any length of time in standby mode. With jet charging technology, the consumption of battery capacity to maintain the operation of the circuit in standby mode and self-discharge is compensated. Stabilization of the charge voltage by negative feedback from the battery to the charging current pulse generator allows you to maintain the charging mode in automatic mode.

Charger Specifications:
Mains voltage 220 Volts.
Maximum charge current 650 mA.
Charge voltage 13.8 Volts.
Battery 12 Volt 1-7a/h.
Fast charge current 350-450 mA.
Jet charging current 30-40 mA.
Discharge current 22 mA.
Charging time 1-2 hours.
Recharging time is continuous.
Time emergency mode 10-30 minutes.
Load power 50 watts.

The uninterruptible power supply circuit includes a pulse charger, in which a constant charging current is converted by a generator on a timer into a sequence of pulses, and the pauses between pulses of positive polarity are filled with a constant discharge current of negative polarity. The battery is loaded with a discharge current during charging, which is used to indicate the connection of the battery to the circuit.

The current converter is made using field-effect transistor switches controlled by a mains frequency generator. In the absence of mains voltage, the mains frequency and level voltage generated by the converter is supplied through the relay to the load; in the presence of mains voltage, it is supplied to the load through the contacts of a relay connected to the network without conversion.

The device has a light indication of switching on, battery connection polarity, high voltage and charging indicator. Sound sensor indicates the absence of mains voltage and warns about taking measures to remove the information storage system from operating mode in a short time according to the program.

Analog timer DA1 (Fig. 1) generates pulses of a stable frequency in self-oscillator mode. The charge-discharge process of the timing capacitor C1 will take place cyclically, the charge time depends on the value of the resistor R2 - T1 = 0.69 C1R2, the discharge time is longer T2 = 0.69 C1 (R3 + R4).

The full period of the pulse is T=T1+T2. The frequency of the self-oscillator depends on the values ​​of the elements R2, R3, R4, C1 - F=1/T. The duty cycle depends on the operating period of the pulse D=T1/T. As the discharge time decreases by decreasing the value of resistor R2, the duty cycle increases.

Diode VD1 generates a short pulse of charging current.
Resistor R3 allows you to set the charge current in accordance with the battery specifications.
The timer is powered by an analog stabilizer DA2, diode VD2 allows you to protect the timer and stabilizer from incorrect battery polarity.

The timer voltage is selected based on the supply voltage of the DD1 microcircuit – the battery voltage converter generator.
Capacitors C2, C3, C4, C5 reduce the level of noise in the power supply circuits.

After power is supplied to the timer DA1 and external circuits, capacitor C1 will begin to charge exponentially to a voltage of 2/3 Un during time T1, after which the internal comparator of the timer at input 6 of DA1 will switch the internal trigger to the opposite state, the internal discharge transistor at pin 7 of DA1 will open, capacitor C1 will begin to discharge to the level of 1/3 Un during time T2.

Charging the battery will follow the same scenario.
Pin 5 in the DA1 timer chip allows direct access to the divider point with a level of 2/3 of the supply voltage, which is the reference point for the operation of the upper comparator. Using this pin allows you to change this level to obtain modifications to the circuit, in this case, to set the output charging voltage on battery GB1. An N-type field-effect transistor is introduced into the circuit as a key current switch, pulses from output 3 of the timer through resistor R5 are supplied to the gate of transistor VT1, the transistor opens and the charge current from the power supply rectifier VD3 through limiting resistor R10 and fuse FU1 is supplied to battery GB1. The HL3 indicator indicates with short light pulses that the battery is charging; the absence of light indicates a break in the battery charging circuit or a faulty transistor VT1.

The presence of power to timer DA1 is indicated by the yellow LED HL1.
The HL2 LED, in parallel connection with the battery, performs three functions, indicates with a green light the correct polarity of the connection of the GB1 battery and is a battery discharge circuit with a current of up to 20 mA. When lit red, the LED indicates an emergency condition or incorrect polarity of connecting the battery to the circuit.

The negative feedback voltage from the positive battery bus through the limiting resistor R7 and the installation resistor R8 is supplied to the control electrode of the adjustable parallel stabilizer voltage DA3 - an integral analogue of a zener diode capable of forming an adjustable exemplary
voltage at pin 5 of timer DA1. When the voltage on the battery increases, the controlled zener diode opens and the stabilization voltage changes.
A decrease in the voltage at the cathode (pin 3 of DA3) leads to a decrease in the voltage at point 5 DA1 of the direct access divider with a level of 2/3 Un, which will lead to an increase in the generator frequency on the DA1 timer and a decrease in the voltage and charging current of the GB1 battery.

A loss of mains voltage causes relay K1 to turn off and contacts K1.1 and K1.2 to switch. The first ones allow the operation of the generator on the DD1 chip by applying to the R input (pin 5 of DD1) low level, after starting the generator, outputs T1 and T2 will be formed square pulses frequency 50 Hz. The pulses are phase shifted by a quarter of a period. To convert rectangular pulses into sinusoids close to the shape, a capacitor C7 is installed at the output of transformer T2. Gas discharge indicator HL3 indicates the presence of high voltage.

The use of field-effect transistors does not require the installation of powerful radiators.
Most of the radio components of the circuit are installed on printed circuit board, the rest are fixed in a housing used from the computer's power supply. Budget fan B1 is used for its intended purpose.

The radio components of the circuit correspond to table 1.

Setting up the device circuit should begin by checking the +16 volt power source and the voltage at the output of the DA2 analog stabilizer. In the absence of battery GB1 in the circuit, the charge current indicator LED HL3 does not light up, HL2 blinks at the frequency of the generator on timer DA1, when the battery is connected, the charge LED will blink and the polarity indicator will light green, if the polarity of the battery connection is correct, if the polarity is incorrect, the LED will light up
red glow. To set the charging current in the open circuit of the battery, connect an ammeter for a current of up to one ampere, use resistor R3 to set the charging current within 0.2 C, and use resistor R8 to set the voltage on the battery to 13.3 volts. After 1-2 hours of charging, the voltage on the battery will increase to 13.8 volts and the current will drop to 0.1C, then in trickle charging mode the current will drop to 0.03C.

The HA1 sound capsule has an internal low frequency oscillator.
Having turned off the mains voltage, use resistor R14 to set the frequency to 50 Hz on capacitor C7.

On field effect transistors VT1-VT3 install small radiators with dimensions 10*50*10 mm.
Install the indication LEDs on the housing on the side opposite to fan B1.

Literature:
1) V. Konovalov “Measurement of R-internal AB” “Radiomir” No. 8 2004 p. 14
2) V. Konovalov, A. Razgildeev. “Restoration of batteries” “Radiomir” No. 3 2005. p.7
3) V. Konovalov “The memory effect is removed by the voltage boost.” "Radiomir" No. 10 2005 p. 13.
4) V. Konovalov “Charger and recovery device for Ni-Ca batteries” “Radio” No. 3, 2006, p. 53.
5) D.A. Khrustalev “Batteries” Moscow 2003
6) I.P. Shelestov “For Radio Amateurs” useful diagrams» book 5. Moscow 2003
7) V. Konovalov “Key charger” “Radiomir” No. 9.2007. page 13.
8) Microcircuit KR142EN19. “Radio” No. 4.1994
9) Pulse charger “Radio” No. 8.1995. p.61
10) Maintenance of “maintenance-free” batteries, “Radiomir” No. 11.2001, p. 13.
11) M. Ozolin “A simple uninterruptible power supply.” “Radio” No. 8.2005, p. 32.
12) S. Biryukov “Primary quartz watches.” “Radio” No. 6 2000. p.34.
13) V. Konovalov “Battery regenerator.” “Radiomir” No. 6.2008 p. 14.
14) V. Konovalov “Pulse diagnostics of batteries.” “Radiomir” No. 8 2008. p.15.

During engine operation, the rechargeable battery (), regardless of the type (maintained or maintenance-free battery), is recharged from the car generator. To control the battery charge, a device called a relay regulator is installed on the generator.

The very operation of a car in winter often involves short trips, turning on a large number of energy-intensive equipment (heated mirrors, windows, seats, etc.) The load on the battery increases significantly. At the same time, the battery simply does not have time to charge from the generator and compensate for the losses spent on launches. Taking into account the above, it is optimal to fully charge the battery with a charger to 100% at least once a year before the onset of cold weather.

Let us add that in case of problems with starting the engine due to engine malfunctions (problems with fuel equipment, etc.), the owner has to turn the starter much longer and more intensely. In such cases, you will need to charge the battery with an external charger much more often.

Charging the battery with a charger

To know how to charge a maintenance-free car battery with a charger, as well as charge a maintenance-free battery, you must follow certain rules. The charger (charger, external charger VZU, jump charger) is actually a capacitor charger.

Car battery - source DC. When connecting the battery, it is imperative to observe the polarity. For this purpose, the connection locations for the positive and negative terminals are indicated by the positive and negative signs (“+” and “–”) on the battery. The terminals on the charger have similar markings, which allows you to correctly connect the battery to the charger. In other words, the “plus” of the battery is connected to the “+” terminal of the charger, the “minus” on the battery is connected to the “-” output of the charger.

Please note that accidentally reversing the polarity will cause the battery to discharge instead of charging. It is also necessary to take into account that a deep discharge (the battery is completely drained) can in some cases damage the battery, as a result of which it may not be possible to charge such a battery using a charger.

It is also necessary to take into account that before connecting to the charger, the battery must be removed from the car and thoroughly cleaned of possible contaminants. Acid stains can be easily removed with a damp cloth, which is moistened in a solution with soda. To prepare the solution, 15-20 grams of soda per 150-200 grams of water is enough. The presence of acid will be indicated by foaming of the specified solution when applied to the battery case.

As for serviceable batteries, the plugs on the “cans” for filling acid should be unscrewed. The fact is that during charging, gases are formed in the battery, which must be provided with a free exit. You should also check the electrolyte level. If the level drops below normal, distilled water is added.

What voltage to charge a car battery with?

Let's start with the fact that charging a battery involves supplying it with such a current that the battery does not have enough for a full charge. Based on this statement, you can answer the questions with what current to charge the car battery, as well as how long to charge the car battery with a charger.

If a battery with a capacity of 50 Amp-hours is 50% charged, then at the initial stage the charging current should be set to 25 A, after which this current should be dynamically reduced. By the time the battery is fully charged, the current supply should stop. This operating principle underlies automatic chargers, with which a car battery is charged in an average of 4-6 hours. The only disadvantage of such memory devices is their high cost.

It is also worth highlighting semi-automatic type chargers and solutions that require completely manual configuration. The latter are the most affordable and widely available on sale. Taking into account the fact that the battery is usually 50% discharged, you can calculate how long to charge a maintenance-free car battery, and also understand how long it takes to charge a maintenance-free car battery.

The basis for calculating the battery charging time is the battery capacity. Knowing this parameter, the charging time is calculated quite simply. If the battery has a capacity of 50 Ah, then to fully charge it is necessary to apply a current of no more than 30 Ah to such a battery. The charger is set to 3A, which will require ten hours to fully charge the battery with the charger.

To be 100% sure that the battery is fully charged, after 10 hours you can set the charger current to 0.5 A, and then continue charging the battery for another 5-10 hours. This charging method does not pose a danger to car batteries that have large capacity. The downside is the need to charge the battery for about a day.

To save time and quickly charge the battery, you can set the charger to 8 A, and then charge it for about 3 hours. After this period, the charging current is reduced to 6 A and the battery is charged with this current for another 1 hour. As a result, it will take 4 hours to charge. Note that this charging mode is not optimal, since it is advisable to charge the battery with a small current of up to 3 A.

Charging with a high current can lead to overcharging and excessive heating of the battery, resulting in a significantly reduced battery life. We also note that the use of battery charging methods, which are aimed at minimizing the negative process of plate sulfation, in practice does not have noticeable positive results.

Correct operation of the battery depending on its type (maintained and unmaintained), avoidance of deep discharge and timely charging using a charger allow acid battery work properly for 3-7 years.

How to assess the condition and charge of a car battery

Proper charging and a number of conditions that must be observed during operation of a car battery can ensure normal engine starting even in extremely low temperatures. The main indicator of the condition of the battery is the degree of its charge. Next we will answer how to find out if the car battery is charged.

Let's start with the fact that some battery models have a special color indicator on the battery itself, which indicates whether the battery is charged or discharged. It is worth noting that this indicator is a very approximate indicator, by which only the need for recharging can be determined with a certain degree of probability. In other words, the charge indicator may indicate that the battery is charged, but the starting current at low temperatures is not enough.

Another way to determine the battery charge level is to measure the voltage at the battery terminals. This method also allows a very rough assessment of the state and degree of charge. To measure, the battery will need to be removed from the car or disconnected from the charger, after which you need to wait an additional 7 hours. The outside air temperature is not of fundamental importance.

• 12.8 V - 100% charge;
• 12.6 V-75% charge;
• 12.2 V-50% charge;
• 12.0 V-25% charge;
• A voltage drop of less than 11.8 V indicates a complete discharge of the battery.

You can also check the battery charge level without waiting. To do this, the voltage at the battery terminals must be measured by load using so-called load forks. This method is more accurate and reliable. The specified plug is a voltmeter; a resistance is connected parallel to the voltmeter terminals. The resistance value is 0.018-0.020 Ohm for a battery with a capacity of 40-60 Ampere-hours.

The plug must be connected to the corresponding outputs on the battery, after which after 6-8 seconds. record the readings displayed by the voltmeter. Next, you can estimate the degree of charge of the battery by voltage using a load plug:

• 10.5 V - 100% charge;
• 9.9 V - 75% charge;
• 9.3 V - 50% charge;
• 8.7 V - 25% charge;
• An indicator of less than 8.18 V means the battery is completely discharged;

You can also take measurements in the absence of a load plug without removing the battery from the car. The battery must be connected to on-board network vehicle. Then you will need to put a load on the battery by turning on the dimensions and high beam head optics (for cars with standard halogen lamps). The headlight bulbs have a power of 50 W, the load is about 10 A. The voltage of a normally charged battery in this case should be about 11.2 V.

The next way to check the battery charge is to measure the voltage at the battery terminals at the moment when the internal combustion engine is started. These measurements can be considered reliable only if the starter is working normally.

At the time of start-up, the voltage reading should not be below 9.5 V. A voltage drop below this mark means that the battery is heavily discharged. In this case, it needs to be charged using a charger. This test method also allows you to identify starter problems. A known good and 100% charged battery is installed on the car, after which measurements are taken. If the voltage at the battery terminals at the time of starting drops below 9.5 V, then problems with the starter are obvious.

Finally, we add that measurements using different methods involve recording fluctuations in fractions of a volt. For this reason, increased demands are placed on the voltmeter. The accuracy of the device is extremely important, since the slightest error of even one or two percent will lead to an error in measuring the state of charge of the battery by 10 -20%. For measurements, it is recommended to use instruments with minimal error.

How to charge a completely dead car battery

A common cause of deep battery discharge is simple inattention. Often it is enough to leave the car with the lights or headlights, interior lighting or radio on for 6-12 hours, after which the battery is completely discharged. For this reason, many car owners are interested in the question of whether it is possible to restore a completely discharged battery.

As you know, completely discharging a battery greatly affects the battery life, especially when it comes to a maintenance-free battery. Manufacturers of car batteries indicate that even one complete discharge is enough to cause the battery to fail. In practice, relatively new batteries can be restored at least 1 or 2 times after they are completely discharged without significant loss of performance properties.

First, you need to determine how badly the battery has been discharged using one of the above methods. You can also immediately charge the battery. Next, the completely discharged battery must be charged in the mode recommended by the battery manufacturer. The standard is to supply a charge current value at 0.1 of the total battery capacity.

A fully charged battery is charged with this current for at least 14-16 hours. For example, consider charging a battery with a capacity of 60 Amp-hours. In this case, the charge current should be on average from 3 A (slower) to 6 A (faster). A completely discharged car battery should be properly charged with the lowest current, and for as long as possible (about a day).

When the voltage at the battery terminals does not increase any more for 60 minutes. (assuming the same charging current is supplied), then the battery is fully charged. Maintenance free batteries when fully charged, the voltage value is assumed to be 16.2±0.1 V. It should be borne in mind that this voltage value is standard, but there is a dependence on the battery capacity, charging current, electrolyte density in the battery, etc. Any voltmeter is suitable for measurement, regardless of the instrument’s error, since it is necessary to measure a constant, not an exact voltage.

How to charge a car battery if there is no charger

The most in a simple way Charging the battery involves starting the car using the “lighting” method from another car, after which you need to drive the car for about 20-30 minutes. For charging efficiency from the generator, either dynamic driving in high gears or driving in low gears is assumed.

The main condition is to maintain crankshaft speed at around 2900-3200 rpm. At the specified speed, the generator will provide the necessary current, which will allow you to recharge the battery. Note that this method is only suitable if the battery is partially, not deeply, discharged. Also, after the trip you will still need to fully charge the battery.

Quite often, car enthusiasts are interested in what else can be used to charge a car battery, besides a charger. Most often, chargers used to charge batteries are supposed to be used as a replacement. mobile phones, tablets, laptops and other gadgets. Let us immediately note that these solutions do not allow you to charge a car battery without a series of manipulations.

The fact is that the main condition for supplying current from the charger to the battery is that there must be a voltage at the output of the charger, which will more voltage at the battery outputs. In other words, if the battery output voltage is 12 V, the charger output voltage should be 14 V. As for various devices, their battery voltage often does not exceed 7.0 V. Now imagine that you have a gadget charger at hand that has the required voltage of 12 Q. The problem will still be present since the resistance of the car battery is measured in whole Ohms.

It turns out that connecting charging from a mobile device to the battery outputs will actually constitute a short circuit of the terminals of the charging power supply. The protection will be triggered in the unit, as a result of which such a charger will not supply current to the battery. In the absence of protection, there is a high probability of failure of the power supply from a significant load.

It is worth adding that the car battery should also not be charged from various power supplies that have a suitable output voltage, but they are structurally unable to adjust the amount of current supplied. Only a special charger for a car battery is a device that has at its output the required voltage and current to charge the battery. In parallel with this, it is possible to control a constant current value.

Homemade charger for a car battery

Now let's move from theory to practice. Let's start with the fact that you can make a battery charger from a power supply from a third-party device with your own hands.

Please note that these actions pose a certain danger and are performed entirely at your own peril and risk. The administration of the resource does not bear any responsibility, the information is presented for informational purposes only!

There are several ways to make a charger. Let's take a quick look at the most common ones:

1. Manufacturing a charger from a source that has a voltage of about 13-14 V at its output, and is also capable of providing a current of more than 1 Ampere. A laptop power supply is suitable for this task.
2. Charging from a regular household electrical outlet of 220 Volts. To do this, you will need a semiconductor diode and an incandescent lamp, which are connected in series in a circuit.

It should be borne in mind that the use of such solutions means charging the battery using a current source. As a result, constant monitoring of the time and moment of the end of the battery charge is required. This control is carried out using regular voltage measurements at the battery terminals or counting the time for which the battery is charged.

Remember, overcharging the battery leads to an increase in the temperature inside the battery and the active release of hydrogen and oxygen. Boiling of the electrolyte in the battery “banks” causes the formation of an explosive mixture. If an electrical spark or other ignition source occurs, the battery may explode. Such an explosion can cause fires, burns and injuries!

Now let's focus on the most common method self-made Charger for car battery. We are talking about charging a laptop from the power supply. To complete the task, certain knowledge, skills and experience in the field of assembling simple electrical circuits. Otherwise, the best solution would be to contact a specialist, purchase a ready-made charger, or replace the battery with a new one.

The manufacturing scheme of the charger itself is quite simple. A ballast lamp is connected to the power supply unit, and the outputs of the homemade charger are connected to the battery outputs. A lamp with a small rating will be required as a “ballast”.

If you try to connect the power supply to the battery without using a ballast light bulb in the electrical circuit, then you can quickly damage both the power supply itself and the battery.

You should select the right lamp step by step, starting with the minimum ratings. To begin with, you can connect a low-power turn signal lamp, then a more powerful turn signal lamp, etc. Each lamp should be tested separately by connecting it in a circuit. If the light is on, then you can proceed to connecting an analogue with more power. This method will help not damage the power supply. Finally, let’s add that about charging the battery from such homemade device will indicate the burning of the ballast lamp. In other words, if the battery is charging, then the lamp will light, even if very dimly.

New battery must be fully charged and operational, that is, it requires immediate installation on the car to begin further operation. Before purchasing, it is necessary to check the battery according to a number of parameters:

• hull integrity;
• voltage measurement at the outputs;
• checking electrolyte density;
• date of manufacture of the battery;

At the initial stage, it is necessary to remove the protective film and inspect the case for cracks, drips and other defects. If the slightest deviation from the norm is detected, it is recommended to replace the battery.

Then the voltage is measured at the terminals of the new battery. You can measure voltage with a voltmeter, but the accuracy of the device does not matter. The voltage should not be below 12 Volts. A voltage reading of 10.8 Volts indicates that the battery is completely discharged. This indicator is unacceptable for a new battery.

The density of the electrolyte is measured using a special fork. Also, the density parameter indirectly indicates the battery charge level. The final stage of verification is determining the release date of the battery. Batteries that were produced 6 months ago. You should not purchase back or more from the day of the planned purchase. The fact is that a ready-to-use battery has a tendency to self-discharge. For this reason, for long-term storage the battery must be prepared in advance, but in this case the battery can no longer be considered a new finished product.

It turns out that the answer to the question of whether a new car battery needs to be charged will be negative. There is no need to charge a new battery. If the battery you plan to purchase is discharged, then it may simply be old, used, or have a manufacturing defect.

Other questions regarding charging car batteries

Very often, during operation, owners try to charge the battery without removing the battery from the car. In other words, the battery is charged without removing the terminals directly on the car, that is, the battery remains connected to the vehicle network while charging.

Please note that when charging the battery, the voltage at the battery terminals may be around 16 V. This voltage indicator greatly depends on what type of charger is used during charging. Let us add that even turning off the ignition and removing the key from the lock does not mean that all devices in the car are de-energized. The security system or alarm system, multimedia head unit, interior lighting and other solutions can remain on or in standby mode.

Charging the battery without removing and disconnecting the terminals may result in too much power being supplied to switched on devices. high voltage nutrition. The result is usually the failure of such devices. If your car has devices that cannot be completely de-energized after the ignition is turned off, then charging the battery without disconnecting the terminals is prohibited. Before charging in this case, it is necessary to disconnect the negative terminal.

Also, do not start disconnecting the battery from the positive terminal. The negative terminal on the battery is connected to the vehicle's electrical network through a direct connection to the body. Trying to turn off the “plus” first can have dire consequences. Unintentional contact of a wrench or other tool with metal parts of the vehicle body/engine will result in short circuit. This situation is quite common in cases where wrenches are used to unscrew the positive terminal from the battery terminal while the negative terminal is not removed.

As for charging the battery in the cold or indoors in winter without heating, the battery can be safely recharged in such conditions. During charging, the battery heats up, the temperature of the electrolyte in the “banks” will be positive. At the same time, it is necessary to bring the battery into a warm place for charging if the electrolyte inside the battery has frozen and the battery has been completely drained. Such a battery must be charged strictly after the frozen electrolyte has thawed.