Do I need to charge a new car battery? Can a charged battery be charged? Is it possible to charge a maintenance-free battery? Is it possible to charge and how to do it correctly?
If you ask a similar question to anyone who has at least some idea about the car and the battery, you can get the most detailed advice. For some reason, many people think that this issue is so trivial that it’s even a shame not to know it. However, statistics show that more than half of the batteries do not withstand the service life declared by the Manufacturer and have to be replaced prematurely with new ones.
And the main reason is improper charging during the operational period. Let's figure out how to charge the battery, and do it CORRECTLY.
Let's make one point clear right away. It is believed that if the car's generator works without failures, and the car is used regularly, then this is quite enough to maintain the proper level of battery charge. This opinion is fundamentally wrong, and here's why. According to its technical characteristics, the generator is not able to provide 100% charging, that is, the battery will always be partially charged, which significantly reduces its service life.
Remove the battery from the car
Often, car enthusiasts neglect this and charge the battery without removing it from the car. But in vain, and here's why.
Firstly, the battery needs to be systematically inspected, from all sides, and not just from above. It is possible that the electrolyte will splash (corrosion of the “mounting” socket frame will appear), or a crack in the housing (the result of constant vibration and unreliable fixation at the location).
Secondly, the product must be cleaned of dirt and dust. The fact is that the “patina” formed on the case, between the terminals, is conductive, which means that the degree of self-discharge of the battery increases, which negatively affects its service life.
Therefore, before charging the battery, it should be serviced. It is good to collect accumulated dirt, which contains acid, with a swab dipped in a weak soda solution. If foaming occurs, this indicates that not all the acid has been removed from the surface of the housing.
By the way, the terminals also require periodic maintenance, since lead oxidizes, and, therefore, more current is required when starting the engine, which leads to increased battery discharge.
If, after all, the battery is charged at the installation site, then the suitable (mains) wires from its terminals must be removed.
Unscrew the caps on the cans
You should also not forget about the need for their maintenance. In the center of each there is a small through hole through which the products of gas formation that occur during operation are removed. If it is clogged with dirt, then the accumulated gas can simply rupture the housing.
In addition, you need to make sure that the electrolyte level is normal. If necessary, add water (distilled).
Connect the charger terminals
Here you need to pay attention to the polarity. The “positive” is connected to the “+” of the battery, the “negative” - to the “-”.
Charging process
This largely depends on the type of device. However, many car enthusiasts prefer to do it manually. The current is set to the maximum (depending on the nominal capacity of the battery), and as the voltage decreases it is added.
It should be noted right away that a lot depends on how the battery is used, to what extent it is discharged, and how often the owner charges it from an external device. The “quality” of the car’s generator also has an impact.
The charging mode with low currents is considered the most optimal. More on this below. It remains to add that it is necessary to systematically monitor this process. Sometimes a car enthusiast simply puts the battery on charge and leaves for a few hours. This risks the fact that the battery may charge earlier (and the recharging process will begin) or even “reset” the current to a minimum. Then you will have to increase it and wait until it is fully charged.
With what we now know, we can answer some common questions that new car enthusiasts have.
How do you know that the battery is fully charged?
The voltage at its terminals can be different (from 14.5 to 16.1 V). This depends on many components (electrolyte density, capacity and a number of others). The main criterion is the constancy of the output voltage at its terminals while the charging process continues for 1 hour. It is measured by any type of voltmeter, regardless of its accuracy class.
Is it possible to do exercises at negative air temperatures?
Yes, since an electrolyte with the proper density never freezes. Example - the car is used not only in summer, but also in winter, and, nevertheless, recharging from the generator is not interrupted.
When charging from an external source, do I need to disconnect the battery from the on-board network?
Necessarily. Quite often, the battery is charged without removing it from its installation location. But here you need to take into account that some electronic device can be connected to the network, even with the ignition and ground turned off. In modern car models there are so many different features of engineering solutions that it is impossible to foresee everything, especially since not all Manufacturers describe such nuances in detail in the documentation for the “car”. Therefore, it is better not to take risks and play it safe, otherwise the higher-than-expected “voltage” of the charger may damage something.
How often should the battery be recharged if it is removed from the car?
Many motorists do not operate their “iron horses” in winter. During this time, a prudent owner removes the battery and stores it separately, in a warm room. But any device characterized by such a parameter as electrical capacitance gradually self-discharges.
Naturally, the electrolyte begins to react to low temperatures, and in a discharged state, in a cold room, the jars can simply freeze. Such a battery can no longer be restored. By the way, this is why it is necessary to remove it for the winter and put it in a “warm” place. Recommendations for recharging frequency vary. To avoid mistakes, it should be done approximately once every 3 months (provided that the battery is stored at above-zero temperatures).
If the battery is not removed from the car and it is not used, then it needs to be charged more often - once every 1.5 - 2 months. This is explained by the fact that it is possible to increase the self-discharge current through the on-board network. And if the wires are removed from the terminals, but it’s cold in the garage, then at least once every 2 weeks. It's more reliable this way.
What current should I set and how long should I charge?
There is a criterion that applies to all types of batteries - the charging current is 10% of the nominal capacity of the product. The most common batteries are 45 A/h (for passenger cars). Therefore, the optimal charge current is 4.5 A. If the discharge is complete, then at least 12 - 15 hours. In other cases - until fully charged. How to determine is indicated above.
Since the degree of rarefaction cannot be determined “by eye”, if the battery is not completely discharged, experts recommend using the “gentle” mode, that is, setting the current to 2 times less than the calculated one (for example, instead of 4.5 A, set it to 2.5). Naturally, it will take more time to charge, but the service life of the product will also increase.
Sometimes, to reduce charging time, car enthusiasts specifically provide increased current. Yes, this way the battery will charge faster. But this does not take into account the fact that the chemical processes occurring in this case begin to occur more intensely, and this entails an increase in the temperature of the electrolyte. Overheating the battery significantly reduces its shelf life.
Experienced car enthusiasts prefer this “technology” - the current is about half an ampere, and let it “stand”. Although it takes longer, it is quite safe for the battery. In this case, charging is achieved at 100 percent.
It remains to add that if you do not allow the battery to systematically discharge to a critical minimum (10.5 V), then the product will reliably serve not only 5 guaranteed years, but also more. Normal electrolyte density within the normal range is 1.25 - 1.27; voltage at the terminals - depending on the type of battery.
Car enthusiasts often ask the question: do they need to charge a new car battery after purchasing it in a retail chain? It is impossible to answer this question unequivocally.
A number of parameters need to be taken into account:
- Battery type. Currently, cars use conventional acid, gel and , the operating principles and charging algorithm of which are different.
- Conditions for storing a car battery before purchase. At the time of selection and purchase, you can ask the seller in which warehouse the batteries are stored (heated or unheated), but the answer is unlikely to be accurate.
- Time from production to sale. The generally accepted maximum battery shelf life is one year. After this storage period, irreversible changes occur in the battery (especially if it has not been recharged during this time), which lead to a loss of capacity and starting current of approximately 5% for each month of storage (average value). It is considered normal to reduce the selling price of a battery by a certain percentage after six months of storage.
- Electrolyte density. This characteristic was the main one for serviceable batteries produced in the last century. Nowadays, not even all service stations have a hydrometer, especially among car enthusiasts, although hydrometers are available for sale.
Modern car batteries are often produced in a maintenance-free version; in AGM and gel batteries there is no concept of electrolyte density at all.
Checking a new car battery during purchase
In large cities, you can purchase a car battery in several ways:
- in specialized stores selling batteries;
- in universal auto parts and consumables stores;
- at car markets;
- in specialized online stores;
- in universal online stores of auto parts and consumables;
- in the gas station network.
Storage conditions largely depend on the place of purchase. If the battery is purchased at a gas station network, it is likely that before the sale it was stored for a long time in an unheated room, often even in a “cage” on the street. Of course, no one recharged it or serviced it. The only advantages of buying at a gas station are that you can hope that the battery will be fairly fresh, and not from the wrong manufacturer.
After purchasing it at a gas station, many car owners immediately install the battery in the car, simultaneously charging it while driving. We are not talking about further recharging here.
Just remember that as soon as the car terminals are connected to the battery, even a completely discharged battery may not be accepted back. In general, the installation of a new battery should be carried out by a certified service station (by the way, you can ask a gas station technician).
Warranties for a car battery may be denied due to self-installation or without documentary confirmation of installation by a specialist (invoice, order, receipt).
Approximately the same picture can be observed in departmental online stores. Their prices may be somewhat lower, but the battery shelf life is likely longer (sometimes such stores repurchase stale goods), and the storage conditions are often unknown.
Video - how to check a new car battery when purchasing:
At the time of purchase, it is better to immediately take a multimeter with you, put it in the mode for measuring constant voltages of 20 Volts, and make sure that the voltage at the terminals is more than 12.4 Volts.
In most cases, the best option for purchasing a new car battery is in specialized online and physical stores that sell batteries. Firstly, the goods are usually not stored in them. Secondly, there are specialists working there who know how to store, maintain and sell batteries correctly.
During the sale (even through a courier), they check the battery voltage using a certified multimeter and the starting current using a load plug. As a rule, there is no need for additional recharging.
Most specialized stores offer free delivery and installation, and if necessary, they buy or take an old battery as credit (and at a normal cost).
In what cases should you charge a new car battery after purchase?
If enough time has passed since the battery was manufactured and charged, then taking into account self-discharge, the battery may lose part of its capacity.
If you install an incompletely charged battery in a vehicle that has not yet been subjected to heavy loads when starting the engine, the following malfunctions may occur:
- starting the engine due to low voltage will take a long time, which can cause melting of the “fresh” battery plates;
- the terminals can become very hot, which will lead to loss of tightness at the points of their entry into the battery case, which in the future can cause the formation of traces of chemical reactions with electrolyte vapor on the terminals;
- If the battery is severely discharged, the engine cannot be started.
Therefore, after purchasing a new car battery, it is advisable to check its parameters and determine whether it needs to be charged.
Voltage control
This is done using a multimeter set to a DC voltage measurement limit of 20 Volts. If the readings are between 12.4 and 12.8 Volts, there is no need to recharge the battery before installing it on the car.
If the multimeter readings are less than 12.2 Volts, the battery should be recharged. Recharging is carried out with a factory charger for 2 - 3 hours with a current corresponding to 0.1 of the nominal capacity. So, a battery with a capacity of 60 ampere hours is charged with a current of 6 Amperes (it is better to take a little less - 4-5 Amperes).
During charging, unscrew the caps on the battery being serviced. The battery must be charged in a non-residential area.
AGM and gel batteries must be recharged. Their charging process has a different algorithm from conventional batteries. It consists of 3 stages: main, additional and recharge. The last stage of pre-sale preparation may be missing; in any case, it is better to do it yourself. It is produced by a charger set to a charge current of 1 - 2 Amps for 5 - 10 hours.
Electrolyte density measurement
Possible only on a serviced battery. A density of about 1.27 g/cm 3 is considered normal. Density is measured with a hydrometer. The density of a new maintenance-free battery can be assessed indirectly by reading the voltage at its terminals.
|
Electrolyte density (g/cm 3 at +20°C) |
Battery charge level, % |
Voltage, V (no load) |
Voltage, V (with load |
Electrolyte freezing point |
Standard hydrometer readings
The hydrometer is a so-called “eye” on the upper base of the battery. If it is in the green zone under load, then the new battery does not need to be charged before installing it on the car. If it displays in a different color, recharging is required.
"Training" battery
Some car enthusiasts adhere to the advice of “training” a new car battery before using it. The so-called training consists of several successive cycles of complete discharge and charging of the battery.
This can be done using a powerful consumer (headlight bulb) and a charger. Such training can be useful if the battery is running low and has slightly sulfated plates (possibly due to improper storage of the battery).
But, if the battery was supplied with a voltage of more than 12.0 Volts, such “training” will lead to nothing but a decrease in its resource.
There is a method for determining the real capacity of a car battery, similar to “training”. To do this, the battery is fully charged, then a load in the form of any powerful headlight bulb is connected.
Video - do you need to charge a new car battery after purchase:
The discharge current is measured using a multimeter. For a 60-watt lamp at 12 volts, it will be approximately 60/12 = 5 amperes.
The winter period is perhaps the most difficult for a car, and in particular for its battery. During cold starts, the battery suffers greatly - it loses charge and cannot be recharged properly because it is cold (as you know, a cold battery charges much worse). And if you travel short distances, for example, 15 minutes by car to work, you end up with chronic “undercharges.” In general, once a month, and maybe more often, you need to recharge with a special charger. BUT here another question arises - how to do this correctly? Do I need to remove the battery or can it be done without removing it from the car? After all, there are so many electronics in cars now that can be burned. Let's find out...
It seems to me that the problem was “pulled out of thin air” out of the blue. All modern chargers can charge your car even if the terminals are not removed from your battery, that is, it is connected to the on-board system. If you are the happy owner of a garage, just come into it, open the hood without removing the battery and terminals (though if they are clean), connect the wires from the “charger” and charge to the required parameters! ALL! Nothing will burn out, nothing will short out, nothing will “fly”. Anyone who says this simply does not understand the structure of a car.
After such a statement, many can now tell me - JUSTIFY, which is what I want to do. However, before that, I want to note that now there are two main types of cars, this is conditionally the “old” carburetor type, they are becoming scarce every year, but they still exist. And the conditionally “new” injection type, the vast majority of cars. In this article we will analyze each option separately. BUT first, a few words about overvoltage.
Overcharge problems
There are a lot of reviews and discussions on this topic on the Internet. Some write that it is necessary to remove the terminals, and if you do not remove them, this can lead to complex breakdowns. Others write that nothing bad will happen and you can charge without removing it. BUT there is NO one opinion here!
I suggest you think logically. From an electrical equipment point of view.
What's wrong with an incorrect charger? YES, it’s simple - high voltage, at which electronic devices can hypothetically burn out, even if they are de-energized through the ignition switch.
So, many chargers produce a maximum voltage of 15V; it can do little for the on-board electronics, since the generator often produces approximately the same voltage.
However, there are specialized charging systems designed, say, for calcium batteries, where the voltage can be 16 - 17V, which can already be critical for many electronic systems.
Therefore, it is initially correct. We take into account that the on-board network can handle 15V MAXIMUM, otherwise we get overvoltage and the possibility of damaging the car’s electronics.
There can be no problems here at all - ZERO. There is simply nothing to burn here, because there is no computer here! Except, but even if it fails, it will most likely simply recharge your battery. BUT the charger has no effect on this relay! How does the charging system of this variant work? The diagram is a little exaggerated, but it is just needed to understand the process.
After starting the engine, the generator begins to produce energy; it is closely connected to the engine crankshaft through a belt drive. The energy is intermittent and is removed by special “brushes” from the rotor. Next, the energy is “rectified” through a special “relay-regulator rectifier”. It provides a constant voltage of, say, 13.8 - 14.2 V, sufficient to charge the battery.
It is clear that when the power unit is operating, the generator powers all other equipment necessary for igniting fuel, lighting, etc., the battery is simply charged in this mode.
The generator cannot recharge the battery, everything is controlled by special “relays”; this is the mechanical principle of charging.
In a carburetor car, there are no specialized control units at all; here many operations are performed mechanically.
Actually, if you do not remove the battery from the car, connect the ends of the charger to the terminals, and the engine will not work at this time. Nothing bad can simply happen, the battery will be charged the same way as from a generator, and the “relay” will essentially be de-energized. Personally, I myself have done this many times, on my VAZ 2101 - 2105.
Injection type
These are modern units that contain a lot of electronics. In general, motors have now evolved very much; they are a bunch of electronics, sensors and other things. The main device that controls everything is, of course, the ECU (Electronic Control Unit). Not only charging is controlled, but also ignition and other vehicle functions. If you tear out this block now, the car will become just a “piece of metal.”
However, for the generator, the evolution is not so noticeable. Again, it spins off from the engine crankshaft (connected by a belt). It again has a “relay-rectifier”, and it again powers the system when the engine starts and recharges the battery.
BUT now power goes not just to consumers, but also to the “brain” of the car’s ECU. This is where the myths were born that - if you connect the charger without removing the terminals, and even the battery itself from the car. Then this “charging” will disable it.
However, this is not true! Let's think logically:
- If the ignition is turned off, then often there is no power going to the ECU. Nowadays, ignition switches are increasingly being installed that turn off all electrical appliances, in order to avoid
- Modern ECUs are fully protected from power surges
- The charger supplies exactly the same voltage as the alternator. I repeat once again from 13.8 to 14.5V (in modern cars), so in principle nothing can burn here
- Also, the “charger” will not burn out either the generator or the starter, because they are simply turned off
- Charger currents, not so large, often range from 2 to 8 Amps
I can assure you with confidence that the battery can be charged without removing the terminals from the car. Nothing bad will happen.
I will say even more - now many sophisticated cars (usually elite class) that have several ECUs, an additional one, can be used for secondary equipment. It is generally not recommended to remove the terminals from the battery. Because certain settings may go wrong, to restore which you will need to visit the stations of an official dealer.
Running engine
This is when you shouldn’t connect the contacts from the “charger” - this is when the engine is running. After all, here the power comes from a standard generator + you also supply power from the charger. First of all, either the generator can be damaged, or the “relay-rectifier” can burn out. Or you can burn the “charger” itself; it is not designed to work with the engine running.
And even in such conditions, the ECU is unlikely to burn out, I want to repeat it again - the charging itself is more likely to suffer.
Dirty terminals and oxides
However, if you want to charge the battery without removing it from the car, you should take care of the car terminals. Sometimes, due to oxides and other deposits, simply moisture, charging will not be possible, or incorrect data will be indicated!
A car battery provides power to the elements of the car. While it is moving, it is charged using a generator. However, he will not be able to fully replenish energy. Therefore, battery maintenance is necessary periodically. To do this, you should know how to properly charge a car battery with a charger at home.
Selecting a charger
The determining parameters are the characteristics of the battery - voltage (6, 12 or 4 V), battery type (flooded, dry-charged, gel and lead acid). Based on the latest quality, it is recommended to choose universal models suitable for all types of batteries. Additionally, the nominal capacity indicator is taken into account - Ah. 
Based on functionality, memory devices are divided into two classes:
- Chargers. Designed only to restore battery functionality; it is possible to maintain the current charge at the required level.
- Starting chargers. To start the vehicle systems, a significant current charge is required. If the battery has not yet been charged by this time, the starting charger can replace it at this stage.
For beginners, it is recommended to buy simple charger models, without additional functions for adjusting parameters. If the car enthusiast has a lot of experience, he will need a professional charger with an indication and the ability to adjust current and voltage. Any model must have the option of protection against overheating and incorrect connection.
How often should you charge your battery?
The frequency at which the battery is charged determines its service life. Ideally, it should be connected to the charger no more than once a year. But in fact it depends on many external factors. If the frequency is incorrectly selected and there is no control over the current state of the battery, the opposite effect will be observed - a rapid decrease in capacity. 
Facts affecting the frequency of battery charging:
- Temperature outside. It does not affect if the indicator is more than +5C. As soon as a decrease occurs, the battery capacity may drop by 1.5-2 times.
- Possible malfunctions of the power plant. These include problems with compression and incorrect functioning of fuel equipment.
- Frequency of full battery load when the engine is off.
The minimum battery charge to start the power plant is individual. But usually it should not be less than 12.3 Volts. If this value is less, the charge will not be enough and you will need to connect to the charger. On average, 70-75% of the maximum charge is sufficient for normal battery operation. It is recommended to restore it to 100% once a year, before the start of the winter period.
Car battery charging methods
There are two main ways to charge a battery - by changing the constant current or voltage. The choice depends on the functionality of the charger, the need to control the process, its speed and degree of charging. 
Before you begin, you must meet the following conditions:
- Preliminary check of the actual battery capacity.
- The correct polarity of the terminals is “plus” to “plus”, as well as “minus”. Otherwise, there will be a reverse process - discharge.
- The minimum cross-section of the wire core is 1 mm2. When braided, the diameter should be about 1.3 mm.
- Cleaning the surface of the battery from acid residues and dirt.
- Unscrew the plugs of the holes intended for pouring acid.
- Checking the electrolyte level. If it is not enough, distilled water is added.
After this, you can begin the charging process. It is recommended to do this in a room with room temperature and good ventilation. As the charge increases, electrolyte vapors will be released.
DC current regulation
The essence of this method is to control the current value by adjusting it depending on the current battery charge. For novice motorists it is difficult, since changes in the indicator depend on the actual condition of the battery. It is recommended to use if it is possible to constantly monitor the process. 
It is best to consider the essence of this method using the example of a battery, the capacity of which is 60A*h. Recommended course of action.
- Set the current value to 6A, from a ratio of 0.1 to the rated capacity.
- After the release of electrolyte gases begins, it is necessary to reduce the indicator by half. If the battery charge is 14.4 V, the current should be 3 A.
- As soon as the charge indicator reaches 15 V, the current decreases to 1.5 A.
In this way, you can charge the battery to a level from 70% to 100%. In the latter case, it is necessary to monitor the battery charge level and current strength. If the first remains unchanged for two hours, this is a sign of full charge.
DC Voltage Change
The best way if it is not possible to constantly monitor the process. It must be taken into account that the battery charge value in this case is proportional to the applied voltage. To preliminary calculate the time, it is necessary to divide the supplied voltage by 1.11. 
Let's consider this process using the example of a standard 12 V battery, depending on the required degree of charge for a duration of 24 hours:
- 75-80%. In this case, the applied voltage should be 14.4 V;
- 85-90%. The optimal value is 15 V;
- 100%. The voltage parameter must be at least 16.3 V.
Important - the charging current value should not exceed 25 A. For this, the charger must be equipped with a circuit that limits this parameter. It is present in all factory models, but if a homemade device is used, this point needs to be tracked.
Checking the battery level
In addition to the parameter values on the charger and battery terminals, it is recommended to additionally monitor the density of the electrolyte. This is done using a special device - a hydrometer. 
For a standard battery, the following values of electrolyte density are accepted depending on the state of charge:
- 100% - 1.28 g/m3;
- 75% - 1.25g/m3;
- 50% - 1.20 g/m3.
It is important to check this indicator in all banks. If for some reason a short circuit occurs in one of them, the value of the electrolyte density will be significantly less than the others. It is also necessary to take into account the error of the hydrometer, the degree of its suitability for verification, and the range of measured values. Additionally, this device can be used to monitor the condition of the coolant.
Alternative methods
A proven method for restoring battery performance without using a special device is “lighting” from another battery. It is important that they have the same current values. Otherwise, the fuses or part of the vehicle's electrical wiring will fail. 
This can be done using the following algorithm.
- Direct connection to the battery of another car, observing the polarity, as when using a charger.
- After starting the engine, you must wait 3-5 minutes and only after that you can disconnect the terminals. First from the “donor”, and then from the battery of your car.
- The trip lasts 20-30 minutes. The best charging will occur when upshifts or downshifts are activated. The recommended crankshaft speed is from 2900 to 3200.
This method will be effective if the battery charge level is not lower than critical. Otherwise, starting the engine and on-board systems will be impossible.
It is also not recommended to use homemade chargers made from household charging blocks from a laptop or mobile phone. It is almost impossible to control the main current and voltage values during the charging process. This can lead to negative consequences. It is best to purchase a cheap but reliable factory charger model.
Many car enthusiasts, when buying a new battery, ask themselves: do they need to charge it?
If it is 95-100% charged, then there is no need for this, but do not rush to put a new battery on the car - it needs to be checked and, in some cases, properly charged. Before describing these cases, let's look at some practical tips for choosing a new battery.
We assume that you have chosen the battery size, capacity, polarity, manufacturer, and now the seller has placed the desired purchase in front of you. Where do we start? From inspection, of course.
Inspect and test the battery before purchasing
First you need to carefully examine it externally. It should not have any deep scratches, cracks, dents, etc. Check for electrolyte leakage. Sometimes during transportation the corners of the case are damaged and cracks form.
Check for protective caps or covers on the battery conductors. If they are not there, check their presence on similar batteries. The absence of caps and covers may indicate that the battery is stale or has already been in use (used as a replacement battery or involved in starting the car).
You need to carefully inspect the current terminals. They must be positioned strictly vertically in relation to the top cover. Sometimes sellers rent out batteries and, as a result of unqualified connection of the terminals or inept handling of keys, the down conductors are bent. Subsequently, problems may arise with the connection of current-carrying wires or with the integrity of the battery case in the area of the current terminals.
On a new battery, the current leads must have a smooth surface; no chips or scratches are allowed. If stripes are felt, then the current conductor has been crimped with a terminal and, accordingly, the battery is used and has already been used.
At all levels, until the battery reaches the buyer, checks are made with a load fork and a multimeter, and the presence of small indented points on the upper edges of the down conductors is allowed.
It is necessary to carefully inspect the filler plugs (if any). They should not show any obvious signs of opening.
The journey from the manufacturer to the store sometimes takes up to six months. Therefore, you should try to choose a battery with a shelf life of no more than six months. It is not recommended to buy older ones. The date of manufacture is engraved on the battery case.
Batteries from foreign manufacturers have their own markings, so don’t be lazy before going to the store, find on the Internet and print out the markings of specific models.
If you are offered to buy a battery that has had six months or more since its release, then it is better to refuse such a purchase. Save your nerves and money.
There are also such situations - you chose a new battery and went to remove your old one from the car. At this time, the seller checks the battery you have chosen, and it is discharged - 12.2 V. If the seller is unscrupulous, then he can quickly put it on charge for a couple of minutes, the voltage will rise, but the state of charge will not increase. The battery will be discharged, but the voltage will show close to normal - 12.7 V. After a short charge, it is simply in the “vigorous” mode.
Also, please note that in hypermarkets such as Auchan, batteries remain sealed without periodic recharging for more than five months. Naturally, without operation and periodic recharging, they lose capacity due to self-discharge. Accordingly, the more time has passed since the battery was released, the more discharged it is.
Battery testing
When purchasing, you should also ask the seller to test the battery using a load fork. We wrote about load forks
Additionally, to assess the condition of the battery, you can use a special tester, for example, OptiMate Test TS120N, from TecMate, retail price is approximately 3,300 rubles.
To test the battery, you need to connect a tester to it according to the wire markings: red to the “+” terminal of the battery, black to the “-” terminal of the battery.
If the red LED is on, the battery is low, the voltage is below 12.5 V.
The green LED is lit - a charged lead-acid battery with a voltage of 12.5-13.1 V.
If the green LED is blinking, there is a charged Lithium/LiFePO 4 battery with a voltage of 13.2-13.5V.
or BatteryBug BB-SBM12, its cost is approximately 1,700 rubles.
This tester only works when the battery is connected to the car, so it cannot be used in a store. This is of course a minus, but it will definitely come in handy on the farm.
For those who are interested in this tester -.
Honest sellers in specialized stores periodically subject the batteries they sell to preventative recharging, so fully charged batteries go on sale, so there is no need to charge them.
But you need to carry out preventative recharging in any case; this does not pose any harm to the battery.
It is better to charge new batteries with a simple automatic device at a constant voltage of no higher than 14.8 V, without any fanaticism, for example, with devices such as Kedr, Katun, Polyus A, Orion, Vympel.
There is no need to use any homemade, manual, Soviet antediluvian devices.
Do I need to charge a new battery?
Many car enthusiasts, when purchasing a new battery, ask themselves the question: do they need to charge the newly purchased battery?
Answer: if the battery is 95-100% charged, then there is no need for this, but if it is discharged, be sure to charge it.
How to understand that the battery is discharged?
The main indicator of charge when purchasing a new battery is its open circuit voltage, where 12.7 V equals 100% charge, and every -0.1 V equals a loss of 10% of the total charge.
For example, a voltage of 12.3 V indicates that the battery is 40% discharged, respectively, the charge is 60%.
If the voltage on the new battery is less than 12.5 V, it is recommended to charge it.
The charge can also be determined by the density of the electrolyte (if the cans can be reached). A density of 1.27 g/cm3 is equal to 100% charge, and a drop of 0.01 is equal to approximately 6% of the total discharge.
In general, according to unspoken rules, stores are recommended to sell only charged batteries with a voltage above 12.5 V.
Many people think it's a light bulb. In fact, this is a simple device consisting of a glass tube and several colored balls. Depending on the level and density of the electrolyte, one or another ball floats up and a different color is visible through the peephole.
You shouldn’t really trust such a system, because the battery consists of six cells, and the indicator is installed only in one, the middle one. And if in any of the other cans the level or density of the electrolyte for any reason does not correspond to the norm, the indicator will not show this.
What is a dry-charged battery and does it need to be charged after purchase?
So-called dry-charged batteries installed on cars, motorcycles, mopeds, scooters, etc. are widely used today.
In dry-charged batteries, the plates are molded and charged during manufacture, but no electrolyte was poured into them when sent to retail chains. After assembly, sealed plugs are inserted into the battery to prevent moisture and air from entering.
What is the advantage of dry-charged batteries? In this condition, the shelf life increases to 5 years.
However, if you buy a dry-charged battery, do not expect that it is ready for use.
What do you need to have to commission a battery and how to do it?
If the purchased battery comes with instructions, you must read it carefully and follow the recommendations!!!
Some types of imported batteries come with a special container with ready-made electrolyte.
If you purchased a battery without a supply of electrolyte, then you need to buy ready-made electrolyte in the required volume.
It is sold in various packaging with a density of 1.27-1.28 g/cm3. The volume of electrolyte should be greater than the volume of the battery. If the battery instructions do not indicate the volume of electrolyte, then it can be approximately calculated based on the geometric dimensions of the case. You may also need distilled water.
You will also need a hydrometer and a charger. You can read how to choose a charger in.
Before starting the process of putting a dry-charged battery into operation, it needs to be prepared: remove the sealing sticker, remove the plugs from the filler necks.
The process of filling electrolyte and subsequent charging can be viewed here
