Screwdriver battery maintenance. We make a perpetual battery for a screwdriver. Structural elements of a screwdriver

The issue of repairing a screwdriver battery is one of the most relevant among the owners of this type of tool. The reason for this is the rather high cost of batteries for screwdrivers, which fail over time. If the battery on the screwdriver has become unusable, then you should not rush to dispose of it. In this case, you can repair the battery of the screwdriver, and what is required for this, we will find out further.

Despite the external design differences in screwdriver batteries, inside these devices have the same structure. At the heart of each device is a set of small cylindrical elements that are connected to each other in a sequential manner. Such elements are called "banks", the external image of which is shown below.

Such "banks" are made of various materials, which is reflected in the cost of a screwdriver. These materials include:

Nickel-metal-hydride (Ni-MH) elements. The rated voltage of each bank does not exceed 1.2 Volts. The final nominal value of the battery voltage depends on the number of such cans.
Lithium-ion. The voltage of each can is 3.6 Volts, therefore, to achieve a similar rating with metal hydride, 2 times fewer cans are required.

Quite rarely, you can already find another type of battery for screwdrivers, which have the abbreviation Ni-Cd. This means that nickel-cadmium cans are installed in such a device. They have already been almost squeezed out of the market by more modern and better types of batteries. Lithium batteries are currently the most popular. The main advantage of lithium devices is the lack of self-discharge, lighter weight, and a large number of charge and charge cycles. Such advantages are reflected in the cost of products, the price of which is 3 times higher than nickel-metal hydride.

Fault definition

Screwdriver battery repair is a replacement for a faulty can. All banks cannot fail immediately, therefore, when the battery is not charging, the reason is hidden mainly in the malfunction of only one battery cell. To repair the battery, you should find this faulty element.

You can determine the malfunction of a failed bank by performing the following manipulations:

Initially, you need to charge the battery until it is fully charged.
We disassemble the case of the device, after which the voltage of each can is measured using a multimeter. The voltage value should be in the range from 1.2 to 1.4 Volts, and for lithium-ion - 3.6-3.8 Volts.
When taking measurements, you can sign the values \u200b\u200bon each jar with a pencil.
After taking measurements, you should reassemble the battery, and then discharge it until the charge is completely lost.
Again we proceed to disassemble the case, and again we check the voltage readings on each element.
If in any bank the voltage drop exceeds the threshold of 0.5 Volts and above, then this indicates the failure of this element.

Many people use this popular method to find a faulty battery cell. There are also other types of battery checks for malfunctions, but the most popular is described above.

It's important to know! Other types of battery failures are very rare and are often associated with low quality products.

After faulty elements are found, they begin to repair them, which is quite realistic to do at home on your own.

Replacing cans in a screwdriver battery

To fix the battery, you need to purchase banks of similar voltage. They can be taken either from an old and faulty battery, or you can purchase new ones. The cost of new nickel-metal hydride cans is quite affordable, and usually does not exceed 100 rubles per can.

It's important to know! The purchased element must match in capacity and dimensions with the rest of the banks.

At home, you can replace a defective element with a soldering iron and tin. In production, such a connection is carried out using spot welding. It is not rational to buy such a device for repairing a screwdriver battery. After the defective element is replaced, you can assemble the battery and check the quality of the repair, for this you need to put it on charge until it is fully charged. After that, and a few hours after the device cools down, you will have to disassemble it again and measure the voltage on each bank. Voltage values should correspond to 1.2-1.3 V.

What are the steps involved in the repair process?

The process of repairing the device is the removal of a faulty can, which is possible by using side cutters, and to connect the battery, you will need to use a soldering iron and its accessories: rosin and tin. Instead of a remote can, solder a working one. However, before working with soldering, it is important to know the following:

Soldering must be done quickly so that the battery does not have time to warm up.
To solder a new can, use connecting plates of the same size.
When soldering, it is important to control the correct connection of the pluses and minuses.

After replacing the defective jar, we check the quality of the soldering, and, if necessary, remove the flux residue. Banks must be assembled, then placed in the device case, and the case must be assembled.

Repair and replacement of battery elements of a screwdriver

It should be noted initially that all types of batteries, both nickel-metal hydride and lithium-ion, are subject to repair. Not many people know how to repair a screwdriver battery, so very often it is faulty batteries that become the reason for buying a new tool.

It is not possible to repair a jar that does not hold a charge, so it will have to be disposed of after being removed from the circuit. Repairing a battery for a screwdriver, in which more than 4 faulty cans are found, is irrational. In this case, it is easier to purchase a new battery entirely, or to find a used device.

In conclusion, it should be noted that most screwdrivers are equipped with two batteries, so if one fails, then the second one will have to be used more intensively during its repair. This will allow the tool not to lie idle, and you can try to repair the product at a convenient time.

Recently, cordless electric tools have become increasingly popular. It is understandable - in some cases, one simply cannot do without such a tool. One of the most important elements in the design of a screwdriver is the battery. Without it, the tool will be useless.

The battery generates direct current during the electrolysis process. It consists of several elements (cans) connected in series. Each bank includes:

Electrodes (anode and cathode).
Electrolyte.
Battery case.

The current is generated due to the appearance of a potential difference between the anode and cathode. Batteries have many important parameters, but the main ones are:

Type, that is, the material from which the poles and electrolyte are made.
Voltage.
Capacity.

The battery voltage depends on its type and number of cells. One bank has a voltage of 1.2 to 3.9 V, depending on the type of battery. Banks are connected in series, due to which their voltage is added.

Battery capacity or maximum battery life depends on the current drawn by the tool and the final voltage when fully discharged. Consider all these parameters using the example of a battery for a Bosch D 70 745 screwdriver. This lithium-ion (li - ion) battery has a voltage of 11.1 V and a capacity of 1500 mAh. A lithium-ion battery has a cell voltage of 3.7 volts and, as can be seen from the total voltage, the battery consists of three cells. Typically, the battery voltage for a screwdriver does not exceed 18 V.

Types of batteries and their features

As can be seen from the above, almost all of its parameters depend on the type of battery. The following types of batteries are mainly used in hand-held power tools:

Nickel-cadmium (Ni-CD).
Nickel Metal Hydride (NiMH).
Lithium-ion (Li-ion).
Lithium polymer (Li-Pol).

More about each type.

Nickel-cadmium

The anode of the NI-MH battery is nickel and the cathode is cadmium. The poles are separated by a separator. The electrolyte is a solution of potassium hydroxide.

Pros:

A large number of charge-discharge cycles (work cycles).
Work well at low temperatures.
Low cost.

Minuses:

Strong memory effect.
High self-discharge.
Big sizes.
Toxicity of materials.
The need to periodically perform a full discharge-charge cycle.

Nickel metal hydride

Nickel-metal hydride batteries were developed to partially replace nickel-cadmium batteries. Their anode is made of nickel-latan or nickel-lithium, the cathode is nickel oxide, and the electrolyte is potassium hydroxide. The cathode and anode are separated by a separator. The case is closed with a lid with a valve that is activated when the battery fails.

Pros:

Higher energy intensity (compared to Ni-CD).
Complete absence of memory effect.
Environmentally friendly.

Minuses:

Fewer charge-discharge cycles.
The need to control the temperature during charging.
High self-discharge.

Li-ion

The anode and cathode in this type of battery is a lithium salt of various acids deposited on the foil. Copper foil is used for the anode and aluminum foil for the cathode. The electrolyte is a gel-like liquid based on lithium salts. The poles are separated by a separator, and an overpressure safety valve is built into the housing.

Pros:

Minuses:

Explosive spontaneous combustion.
Low operating temperature range.
High price.
Strong discharge, overcharging and heating are unacceptable.

Lithium polymer

Li-Pol batteries are an improvement on lithium-ion batteries by replacing the liquid electrolyte with a polymer one.

The pros and cons of this type of battery are similar to those of lithium-ion batteries. But unlike them, Li-Pol batteries are safer in terms of spontaneous combustion, subject to the charging mode.

Do not attempt to replace a failed battery of one type with another. If lithium-polymer and lithium-ion batteries are interchangeable to some extent, then lithium batteries with nickel batteries are completely interchangeable.

Watch the degree of discharge. Try to charge the battery immediately after it has sat down. Otherwise, due to the self-discharge effect, the voltage may drop below the permissible level, and the battery will fail.
Charge the tool only with the charger supplied. If it breaks, replace it with a similar one or select the one that suits your parameters. Violation of at least one of the charging mode parameters will lead to battery failure.
As a rule, lithium batteries have an overcharge and over discharge protection circuit, when repairing, be careful not to damage it. Otherwise, you will have to use a special device when charging, manually controlling all parameters, and charge the battery before it runs out completely.
Monitor the temperature of the battery during operation and charging.
Do not damage the battery.
Store the battery in a partially or fully charged state, and for long-term storage, charge the battery at least once a month.

Basic faults and battery checks

Subject to operating conditions In handheld power tools, the battery most often fails. Battery symptoms:

Significant reduction in run time.
Not charging or charging very quickly.
External damage.

Depending on the type and parameters of the battery, the price for them can vary greatly. Powerful lithium batteries can be commensurate in cost with a new tool, in which case you can try to repair the screwdriver battery yourself.

Before you start repairing the battery at home, you need to determine the type of malfunction. The main types of faults:

Violation of contacts.
Mechanical damage to cans.
Natural aging.
Degradation due to misuse.

To check the integrity of the contacts, it is necessary to disassemble the battery case and visually inspect all soldering points. At the same stage, it will be possible to inspect all the battery cells and make sure there are no mechanical damages.

In the event of natural aging or cell degradation, the total voltage of a fully charged battery is reduced. This can be detected with a multimeter, but not all owners of hand-held power tools keep it at hand.

Battery repair and restoration

The general principles for repairing various types of batteries are similar. For example, the recovery methods for Ni-CD screwdriver batteries are similar to the repair methods for nickel-metal hydride batteries. But more on that below.

To repair the battery, you must perform the following basic operations:

Full discharge-charge cycles are necessary to eliminate the accumulated memory effect and attempt to equalize the voltage between the battery cells. In this case, a good option would be to use special universal chargers that allow you to set the charge-discharge voltage. We set the voltage 2-3 times less than that indicated on the charger included in the kit, and perform the cycles. At the end, we get a fully charged battery.

We disassemble the battery. There can be two options here: either it will be necessary to unscrew the screws that tighten the battery case, or, using a small hammer with rubber pads, carefully separate the parts of the case. In the second case, it is important to find the junction of the body halves. At the end of the procedure, we remove the soldered battery elements from the case.

At the next stage, we perform a visual inspection of the elements, paying special attention to the integrity of the contacts and soldering points.

After that, we move on to the whole and its each element separately. Depending on the type of can and their number, the total voltage may be different. For a nickel-cadmium and nickel-metal hydride battery, it is 1.4 V per cell, for lithium - 3.6 - 3.9 V. We measure the voltage when the battery is fully charged for each cell. For convenience, it is better to write down the testimony.

Then we discharge the battery (we supply power) until a noticeable loss of power and repeat the voltage measurement procedure. The Ni - CD and Ni - MH type element must be replaced if its voltage is below 1.2 V when fully charged and below 1.0 Volts when discharged. For a lithium can, these figures are 3 and 2.2 V, respectively.

Let's move on to troubleshooting. Swollen cans or cans with a breach of the tightness of the body cannot be repaired, they must be replaced. Broken contacts must be soldered again.

Elements with a low voltage reading are best replaced with new ones. In order to save money, you can take the cans from another used battery, but it is important to remember that after some time these cans will also require replacement.

On some resources you can find information about the recovery of Ni - CD and Ni - MH cans using electrolyte renewal. To do this, you need to make a hole in the jar, pour water into it and solder the hole. But the problem is that the density of the electrolyte must be in a certain range and it will be very difficult to “get” into it at home.

Violation of the tightness of a lithium can, as a rule, leads to its complete failure. Therefore, lithium cans cannot be repaired. In the event of a breakdown of the overcharge control circuit in lithium batteries, it can be resoldered.

Considering the cost of nickel cans, the best way to replace failed elements is to buy new ones. Separate new elements are available for sale, but in this case it is important to pay attention to the manufacturer. On factory-made banks, there is usually a marking, in case of its absence, it is worth thinking about buying.

After eliminating the identified malfunction, it is necessary to assemble the battery, fully charge and check the total voltage. If everything is done correctly, the screwdriver will work like new.

As you can see, it is not difficult to restore and repair a broken battery for a screwdriver, it all depends on your skills and the availability of a soldering iron and a multimeter. Their cost, if not available, may be higher than the cost of the battery itself. On the other hand, a soldering iron and a multimeter will always come in handy on the farm.

If you doubt your abilities or simply do not want to repair the battery yourself, it is better to take it to a specialized workshop. Such workshops or service centers are always available in large tool stores. On the other hand, service center specialists do not always perform repairs with high quality, and often delay the deadlines.

Reading 11 min. Published on 29.11.2018

Skip talking about the benefits of screwdrivers, you can go straight to the topic. The battery or accumulator for screwdriver owners is the biggest concern. It is better to handle them strictly according to the instructions. In the event of a breakdown, the only solution is to buy a new battery. But temporarily you can try to use the problematic battery, for which a number of tips are offered. We emphasize that battery repair is a temporary solution, but first you need to accurately investigate the causes of the malfunction.

Types of batteries and their differences

The power source for a hand tool should provide it with energy for at least half an hour of operation at moderate load or 10 minutes at full load. And at the same time quickly enough to restore your charge. Without fulfilling these conditions, the instrument loses all commercial meaning, it simply will not be bought. Typically, the power of a screwdriver varies between 80-160 watts.

Of all the types of batteries that the industry produces, only three types fit these criteria:

Ni-Cd - nickel-cadmium;
Ni-MH - nickel-metal hydride;
Li-ion - lithium-ion.

Nickel-cadmium appeared before all the others and showed good performance properties. Such a battery has a voltage of 1.35 V ... 1.0 V. Here and below, we designate the nominal voltage as the first, and the voltage at the end of the discharge cycle as the last. Ni-Cd have a number of charge / discharge cycles ranging from 100 to 900, it depends on the quality of the materials and the mode of operation. Ni-Cd is also characterized by a very low internal resistance, they almost do not heat up when charging, and are stored for a long time.

Flaws:

"memory effect" interfering in operation.
Toxicity of cadmium, it is a strong carcinogen.

Another type: nickel-metal hydride battery. These batteries have been proposed as replacements for Ni-Cd. The rationale was the shortcomings of traditional batteries with cadmium. In theory, Ni-MH is good: it has a high energy intensity (up to 300 Wh / kg), it is not subject to the memory effect. Voltage 1.25 V ... 1.1 V, number of charge cycles 300-800. Ni-MH of the old type is completely self-discharged after a year of storage. It is recommended to store them at a low temperature, from 0 to 20 degrees Celsius. Batteries of the new type LSD Ni-MH (Low Self-Discharge), as their name shows, have a low self-discharge and heat up less when charging.

Disadvantages: Ni-MH batteries are 10% discharge during the first day, and significant heat generation during charging.

Li-ion batteries have a voltage of 3.7 V ... 2.5 V, but in reality it is a little more complicated, it all depends on the battery usage mode. The number of charge cycles is approximately 600, but this is provided that no more than 20% of the capacity is taken from the battery. Lithium-ion batteries really don't like deep discharge. Because of this, they quickly fail. The internal resistance of Li-ion is very small, 5 ... 15 milliOhm. Self-discharge of about 1.6% per month when fully charged and no load.

Disadvantages: high cost, limited shelf life independent of use. Explosion and fire hazard if handled incorrectly.

Battery fault diagnostics

It is not necessary to suspect a malfunction of the screwdriver battery or to restore it immediately, but first try to replace it with the second one from the kit, before charging it properly. If the screwdriver does not rotate well, then this may be caused by breakdowns in its mechanics (motor or gearbox). If in doubt, replace the power supply, if possible. If everything points to the battery, then you can start diagnosing and restoring it.

First of all, you need to find out the type of battery. This is written on its body and the possibility of recovery depends on it. The rated voltage must also be specified. It usually lies within 14 ... 19 V. Then, without disassembling the case of the battery pack, it is checked. Two methods can be used for this:

Checking with a multimeter;
Load check.

Multimeter Method

The multimeter can be used in two modes: voltage measurement and current measurement. If there are two devices, then this is even better, you do not need to make unnecessary switches.

The measurement scheme is shown below:

One multimeter switches to voltage measurement mode (voltmeter), the other to current measurement mode (ammeter). If there is only one device, then instead of an ammeter you will have to use just a wire. The wires from the battery to the voltmeter can be thin, and the wires from the power source to the battery can be thicker, but do not get too carried away, in the end, 0.5 mm.sq.

If the battery voltage is normal, but the charge current is low, much less than one ampere, then for a Ni-Cd battery this may indicate a malfunction of one of the battery cells. Restoration of the battery of the screwdriver is canceled here, repair is needed. For Li-ion, this means that either it is normal, or also a malfunction of one of the elements.

Let the Ni-Cd battery have a nominal voltage of 18 volts. Then it's easy to find out how many elements are inside without opening the case. Knowing the nominal voltage of Ni-Cd 1.2 V, divide: 18 / 1.2 \u003d 15. This means that there are 15 elements in the case. If the voltmeter shows an idle voltage of 16.8 V, then this may mean a short circuit in one of the cans, or simply a discharge of a normal battery. Such a battery in a discharged state gives 15 V. If a charged one shows 16.8 V or so, then one of the cells is shorted. It can't be repaired either, you'll have to replace it.

If the battery, when charging, passes a current of more than one ampere, and the voltage gradually increases, increasing by 0.1 V every 5-10 minutes, and at the end of the charge the voltage is slightly higher than the nominal value, then the battery is in order, recovery is not required.

Load method

This method is similar to the previous one and it is perhaps simpler. No need to disassemble the charger, or use a laboratory power supply. You only need:

Automotive light bulbs;
Multimeter;
Pieces of wire;
Soldering iron with solder and flux.

Check scheme:

For such a check, you must first put the battery on charge and charge in the usual way. Then the rated load is applied. Finding out the current is easy, for this, divide the power consumption by the rated voltage. For example, if a screwdriver consumes power of 50 W (typical case), at a voltage of 18 V, then the current should be 50/18 \u003d 2.77 A. You can achieve this current, or close to it, by dialing car bulbs from turns in parallel.

If the battery delivers rated current for several minutes, the voltmeter shows a voltage slightly lower than the nominal value, and the lights do not dim, then the battery is working. It may, however, happen that for Ni-Cd the current will soon begin to weaken. This is a manifestation of "memory". In this case, you need to restore. Lithium-ion batteries do not have a memory effect, although in theory it exists, in practice it is believed that it simply does not exist.

Element Check

This method requires disassembly of the battery case. It is used when the battery or its cell ceases to give a good current, and recovery attempts are unsuccessful. One bad link is enough here, since they are connected in series. But to find such an element, you need to check the internal resistance of each of them.

Of course, you need to start with a general inspection of all cans: are there any cracks, leaks, etc. A faulty element will immediately give itself out in appearance.

The current output is checked using Ohm's law for a complete circuit (aka Kirchhoff's first law). To do this, you need to take a resistance with a nominal value of 10 ohms, designed for 25 watts, and an ammeter. The element under test is shorted to a resistance connected in series with the ammeter.

For example, suppose a current of 100 mA is obtained for a Ni-Cd battery with a voltage of 1.2 V. Let's write it down and re-measure, but not the current, but the voltage on the element. First we measure the idle voltage, without connecting the resistor, and then we connect the resistor and see how much the voltage has dropped. Let the first time it was 1.2 V, and after connecting the resistor it became 1.05 V. Then the internal resistance of this element:
This is not too small, if all the elements are like that, then the battery will only be able to provide a screwdriver with half the power. The lower the internal resistance, the better the element, but under an indispensable condition: it must give a nominal voltage, or close to it. If the voltage is too low, or very close to zero, then the element has shorted out, it is no good and cannot be restored. If the internal resistance is greater than 3 ohms, then you can try to restore (see below) or replace.

How to restore the battery?

There are several ways to achieve normal battery operation and reanimate it at home. First, it is the restoration of a normal charge-discharge cycle. You can also, in case of failure, open the battery case as a last resort and examine the individual condition of the cells. In some cases, this allows you to completely repair the battery (if there are similar ones for replacement).

Eliminate the memory effect

This recovery method is applicable to nickel-cadmium batteries. It is very easy to execute it. First, the battery is completely discharged by a screwdriver or other load, such as lamps or resistance. Then it is fully charged. And this needs to be done several times. If the battery has no other defects, then it will be completely restored. It makes no sense to restore lithium-ion batteries in this way.

There are ways to “recover” with an asymmetric current, when the charging current pulse is larger, and the discharge gap following it is smaller, so that the difference is positive. This method is wrong, it does not take into account the fact that chemical processes are much slower. Even wilder is the method of recovery with high current pulses. They should not be used.

To restore a Ni-Cd battery, you will need:

Charger;
Several car light bulbs;
Copper wire 0.5 ... 0.75 mm.kv;
Multimeter.

It is better, of course, to have an uncomplicated special stand for restoration, but this is more suitable for professional repairmen than ordinary screwdriver users. But be that as it may, working with two multimeters is much more convenient than with one.

The recovery steps are as follows:

In practice, do from 3-4 to 7-8 cycles. If condition 11 cannot be reached in the recovery algorithm, then the battery must be repaired.

Adding distilled water to the Ni-Cd battery

This is done when disassembling the case and if the internal resistance has increased (significantly more than 0.3 ... 0.6 Ohm). With a small drill (0.5 mm), the body of the element is carefully drilled and a few milliliters of pure distilled water are injected into it with a syringe. Then the hole is sealed with a soldering iron. These manipulations require skill and may not succumb to a beginner.

After some time, about 12-24 hours, the electrolyte will return to its normal state and the cell will recover for a more or less long period.

To complete the work you will need:

Mini drill + drill 0.3-0.5 mm (in extreme cases, a strong awl);
1 ml syringe with needle and distilled water;
Soldering iron 40-60 W, POS-61 solder and flux.

Where to make the hole:

The sequence of actions is as follows:

Cut along the axis of the paper cover from the element and remove it;
Drill, as shown in the figure above, a hole. The drill should go 3-4 mm, no more;
Introduce 10-15 ml of distilled water into the hole made;
Wait 12-24 hours until the entire volume is soaked;
Charge the cell up to the nominal voltage;
Solder the hole with a well-heated soldering iron;
Put on a paper case and seal it with tape.

Recovered cells can be collected into a battery.

An example of how to do it yourself in the video:

Resuscitation by replacement

This is the most technically competent type of repair, since chemical current sources are considered non-separable and beyond repair, they can only be disposed of at the end of their service life.

For such a repair, two faulty batteries can be used, and the probability of making “one out of two” is very high. The elements must be of the same type and size. And also preferably close in time of manufacture. During assembly, the conclusions must be soldered with high quality, and the entire assembly must be placed in the case without tension and effort.

For work you will need:

Sharp cutters;
Soldering iron 40-60 W, POS-61 solder, flux;
Stranded mounting copper wire with a cross section of 0.75 mm.kv;
Tape or duct tape.

Here is the order of work:

Disassemble the block (and possibly one more) of batteries;
Check each of the elements (see above);
Select the highest quality;
Remove the old tire;
Quickly and thoroughly tin soldering points;
Solder the connections with pieces of wire;
Collect the elements and wrap once with tape;
Assemble the block.

ADVICE: In order to avoid problems with tinning of elements, which in no case should be overheated, you need to warm up the soldering iron well and use an effective flux. An aspirin tablet fits. Do the work while extracting the air, as the decomposition of aspirin produces harmful and irritating substances. Rinse the remaining flux with acetone or alcohol.

Release of gas from Li-ion batteries

As a result of improper use of Li-ion cells (abuse of overdischarge), swelling is possible. As a result of the decomposition of salts, oxygen is released and creates a high pressure in the housing of the sealed element. These gases are released using special valves, but may not be present in small cells.

ATTENTION! Forcibly releasing gas from swollen Li-ion batteries by destroying their case is strictly prohibited by any instruction for their operation, this is a gross violation of fire safety!

The consequences of such an autopsy can be seen in this video:

Conclusion

Batteries for screwdrivers are best operated by following the instructions. Discharge Ni-Cd batteries to 0 before the next charge, and recharge Li-ion batteries as often as possible. Only dry nickel-cadmium cells are subject to partial recovery, lithium-ion cells are not subject to recovery. Be careful when handling batteries!

The ability to work with a tool such as a screwdriver without connecting it to the mains is convenient, practical and, most importantly, necessary. After all, it is often necessary to perform any work in those places where it is almost impossible to reach the network cable. Construction tool stores carry a wide variety of screwdrivers, including Bosch, as well as the popular Hitachi and Makita. But, unfortunately, the battery life of any drill or similar tool is short - a maximum of 5 years. Sometimes even after a shorter period of time. Urgently buying a new battery is unprofitable. For the same amount, you can buy a new screwdriver. Therefore, it is worth trying such an option as do-it-yourself screwdriver battery recovery.

Types of batteries used in screwdrivers and their differences

As you know, the battery of any screwdriver includes several batteries that are connected in one chain in a certain sequence. There are (Ni-Cd), nickel-metal hydride () and elements.

Nickel-cadmium batteries, in this case, are the most common and frequently used. The voltage of each individual element is 1.2 volts and the capacity is 12000 mAh if we have a 12 volt tool. It should be noted right away that, unlike lithium, they are subject to recovery, because they have the so-called "memory effect" in the form of a reversible loss of capacity.

As for batteries containing lithium, it is unlikely that it will be possible to restore their capacity using the popular Imax B6 charger - due to the fact that lithium tends to decompose over time.

Repairing a screwdriver battery in the same way may also fail for cadmium batteries. Such a battery is different in that the electrolyte in them sometimes completely boils away. However, in the case of cadmium batteries, the chances of "reviving" them are much greater. But at the same time, it is important not to rush and not use the common methods of "quick recovery" Ni Cd batteries in haste.

How to restore a screwdriver battery

There are a large number of videos on the Internet, which, for example, clearly show the battery recovery of a Hitachi screwdriver using the Imax B6. It consists in "reanimating" nickel batteries by supplying high currents. Supporters of the express recovery method offer to revive the battery using the simple settings of the Imax B6. The mode is set to nickel-cadmium, and the battery can be revived in this mode.

However, warming up with pulsed power and subsequent charging are rather risky methods for nickel-cadmium batteries. The broken connection in the element cannot be restored by high currents. In addition, if there is little or no electrolyte inside the battery, high currents will finally “kill” the battery. Therefore, in order to prevent irreversible damage to the batteries, it is recommended to first replenish their electrolyte supply with distilled water and only then charge them with the Imax B6.

There is an extreme option on how to restore the nickel-cadmium battery of a screwdriver - you can “pull” them with high current. They will start charging, but not for long. Electronics lovers who criticize this method claim that there has not been a single case of a pulsed current restoring the battery capacity for a long time. As a rule, it rises for a very short time, and then, after a few days, the battery “sits down” again.

Whether it is possible to use the method of pulsed current is up to the owners of the batteries. There are many videos on the Internet on how to restore a Ni Cd battery from a screwdriver. But there is an opinion that in reality, fast methods work for a very short time. For example, if the electrolyte inside a battery boils away or dries up, the pulsed current will “kill” the cell completely.

If possible, you can carefully disassemble each nickel-cadmium battery and see what state the electrolyte is in. If it turns out to be dry, you can use the method of adding a small amount of distilled water through a syringe.

Recovery with water

In order to drill a neat hole in the battery, you need a small drill. The hole should be made away from the center, preferably in the upper side of the element, where there is a small indentation. Then fill the battery with distilled water using a syringe to the last.

After that, the battery can be fully charged Imax B6 and let it "settle". The procedure is long. Recovery of 8-, 12-, 14-battery "cans", depending on the voltage, can take a long time. Ideally, you should not charge them immediately, but give the “banks” of water time to stand for a day. Batteries cannot be charged one at a time, it is better that there are at least three or four of them in a bundle, for even distribution of voltage.

Short-term current pulses through a resistance of 40 ohms at 12 V should be applied after water has been poured into the reanimated element, and not “dry”, as is often done.

After the batteries have stood for a day, you can start charging them. Do not close the holes yet. Connect to Imax so that the device "sees" them. Charge and let it “settle” again if any one battery has not recovered. Find the weak element in the bundle with a multimeter and add water to it again.

The main essence of this meticulous method is to restore the connection of the battery plates with their contact-adapter busbars. (The internal structure of Ni-Cd is similar to the scheme by which solar panels are manufactured). The main reason for the termination of the batteries is the detachment of the positive contact from their inside.

Do not cover the holes drilled in the batteries until the battery charge is stable. As soon as the charge stabilizes, carefully seal the holes with silicone. Water can be added periodically at any time.

As it has already become clear, this method is not intended for the lazy and for those who do not want to delve into the intricacies of the electronics device. However, the distilled water method saves a lot of money and is the answer to the question of how to restore the screwdriver battery in the most gentle way. Usually, two batteries are included with the screwdriver. One can be used, and the other gradually restored. This method, despite its duration, seems to be more humane and safer for the battery.

Battery recovery by replacing several elements

Repairing a screwdriver battery by replacing several cells can be successful for all types of batteries. It also does not pose any risk to them, as does manipulation with distilled water, provided care is taken during soldering.

First, using a multimeter, the output voltage of each “can” is measured, which in total should be 12-14 V. Accordingly, the voltage of one “can” should be 1.2-1.4 V. The U indicators are compared with each other, the most weak elements.

After that, the battery is inserted into the screwdriver and works until the moment when the power begins to noticeably decrease. The voltage indicators are taken again, and those "banks", the voltage difference of which is 0.5-0.7 V compared to the more "stronger" ones, should be soldered out and replaced with new ones similar to the old ones, after ordering them in the online store.

It is recommended to solder the battery chain by spot welding, but if there is none, there is nothing left to do but use a conventional soldering iron and do everything as quickly and accurately as possible in order to prevent the battery from overheating as far as possible.

The "native" battery connecting plates should not be lost, they should be soldered back without reversing the polarity. In addition, all elements of the chain must have the same capacity.

After soldering, insert the battery back into the screwdriver and carry out 2-3 full charge-discharge cycles to equalize the energy potential of all batteries. In order for the updated battery to last longer, such training should be carried out 2-3 times a month.

Restoring the battery of a screwdriver by purchasing new Ni-Cd elements

In this case, we are talking about the complete and so-called "erasing the memory effect" from new batteries in order to ensure their more productive work. The memory effect is that the battery "remembers" all the possible charge cycles that it could theoretically be subjected to in production before falling into someone's hands. The more such cycles in its "memory", the more likely it becomes that the capacity will begin to decrease much earlier than expected. Nickel-cadmium batteries also love such "buildup" processes. If they are carried out immediately before use, they will work much better.

The required number of batteries can be ordered online, for example, on Ali-Express. It must be borne in mind that they already have a certain factory charge, which is desirable to "remove" in order to "save" the power of the batteries during operation. This can be done using the same Imax B6 charger, the menu of which is easy to figure out.

Suppose a screwdriver battery should consist of 10 cells with the following indicators: the output voltage of each is 1.2 V, and the capacity is 1200 mAh, which is 12 V in total. is that in any online store you can order items with higher capacity than the old ones. For example, 1800 mAh. And the battery will last much longer. Of course, these batteries will cost more. But their price is always justified.

First, the voltage on each “bank” is checked with a multimeter. This will immediately help to determine what quality new batteries have and whether there is dishonesty of sellers who could sell old cells instead of new ones. The voltage level on each battery should be approximately 1.3 V. When measuring, it is important not to confuse the terminals.

Further, "memory erasure" is carried out with each element in turn. The following charge parameters are set on the charger: if the capacity is 1800 mAh, it can be set a little more - 1900, a little with a margin. Then you should switch to the charge mode for nickel-cadmium batteries. The charge parameters should be as follows: current indicator 0.9 A (half of the capacity of 1800).

Each new element is subjected to training on the principle of "charge-discharge" to remove the factory settings. At a current of 1A, all batteries are discharged in turn to a voltage of 1 V (the minimum allowable voltage so as not to kill the battery).

Then you should switch to the "charge-discharge" cycle mode and start it with the "start" button.
After discharging and removing the factory memory, put the batteries back into the block, focusing on how the old ones were put there before. Therefore, when disassembling the plastic case, you need to remember how the batteries lay before.

Thus, there are many ways to restore the battery of a screwdriver with your own hands. Each of them has certain nuances, disadvantages and advantages that should be considered depending on how you restore capacity. Sometimes you should try to get this or that tool or the necessary ingredient (for example, distilled water) in order for the recovery to be as successful as possible. But this is exactly what will help you avoid additional costs in connection with the purchase of a new screwdriver or a completely finished battery.

Every piece of equipment breaks down from time to time. This also happens quite often with screwdrivers. No one wants to take on an ordinary screwdriver after they have appreciated the advantages of this type of device. Batteries fail most often. Do not rush to throw away a defective battery. Do-it-yourself screwdriver battery repair is not difficult if you follow the instructions in this article. Before starting work, you need to prepare the tools.

Determining the type of battery

To determine the content of the battery, it is necessary to disassemble its case. The internal components are several batteries connected in series. For the most part, it is these batteries that are integrated, but their disadvantage is the property of intense self-discharge. The battery charge is depleted if the battery is not used for a period of time. Most of the devices are made according to this principle, despite all the inconveniences.

The creation of nickel-cadmium elements does not require special education, special skills. The cost of hazardous production is reduced due to cheap labor. This contributes to an increase in profitability indicators. Production technology harms the environment, the health of workers, creates inconvenience for buyers, but brings profit to entrepreneurs. In essence, battery cells for repairing a screwdriver are nothing complicated. Everyone can repair them.

Fault definition

It will be necessary to determine the place of the electrical circuit break and remove the failed "jar". This can be done with an ohmmeter or tester. The total resistance of the battery is determined and divided by the number of integrated "cans". Quite a simple procedure. Thus, the resistance of each battery is calculated. But in this case, there are still some nuances. It will not be possible to measure the resistance if there is an open circuit.

You will have to check each "bank" separately. The readings will vary, but the resistance of some battery cells will be significantly higher than the average value. Quite often on the "banks" their operating parameters are indicated. An example is the Makita screwdriver battery.

What to do after identifying a defective item?

This marking greatly simplifies the work. The indicated value can be compared with the data obtained after the measurement. A "bank" will not be usable in the future if its resistance deviates sharply from the parameters on the marking. You will need to remove this element from the circuit and replace it with a working one. Such details may not always be at hand.

You can try to find a donor battery for a Makita screwdriver of some other brand, developed using a similar technology. Today, this method will not cause problems. All kinds of batteries constantly fill the collection points for used components. It is possible to find the necessary battery.

It makes sense to ask for help in special workshops. The necessary element is sure to be found. Of course, it is financially expedient for the craftsmen at these firms to repair on their own, but they will not refuse to help with the search for a new “bank”. Many people repair the battery for the Interskol screwdriver in this way.

Recovery

Li-Ion batteries are not recoverable because they do not have a "memory effect". Consider a Ni-Cd type battery. For its restoration, the compaction method is suitable. The battery banks are neatly compressed. In this case, slight deformation of the body is allowed. The voltage flashing method makes it possible to get rid of the "memory effect" to restore the nominal capacity of the battery "can".

Potential equalization

Restoration allows you to temporarily improve the condition of the battery, and do-it-yourself repair of screwdriver batteries with the replacement of components will contribute to their renewal. After working on all elements, it is necessary to equalize the potentials. To do this, the battery is fully charged and the day is idle. The multimeter reading should be 1.2 V on each bank. Then you need to eliminate the "memory effect".

The battery is discharged and charged several times. As a preventative procedure to prevent the appearance of unwanted memory, this action must be repeated every three months. This will significantly extend the life of the screwdriver until there is a desire to purchase a new one.

How to replace the tester?

An ohmmeter or tester may not be in the existing set of measuring instruments. An ordinary LED light bulb will help identify a faulty "jar". You need to solder two wires to it. Opposite contacts are attached to the poles of all battery cells. There is no need to solder the entire circuit.

The light bulb will receive a charge from a separate element. A weak link will be found in the electrical circuit when there is no glow. Do-it-yourself screwdriver battery repair after determining the faulty element is nothing complicated. Do not rush to remove it, try to squeeze the "jar" from all sides without causing damage to the case.

The cell can last for some time, when the density of the remaining electrolyte increases by squeezing. The “bank” will have to be soldered if the LED does not light up after compression. If there is no time to select and replace components, the screwdriver battery device can be repaired by soldering the contacts in place of the removed part. The tool will lose power, but will work.

Proper use of the instrument

In order for the 12V battery for a screwdriver to function continuously and stably, it is necessary to charge it to the maximum once a month, and then completely discharge it during use. You need to develop his energy. Even idling can be effective. Do not overload the tool. Preferable in the mode of operation of the screwdriver will be small natural breaks, which is typical for the normal operation process. The battery is discharged to the maximum and put on charge again.

This procedure should be repeated 2-3 times. The battery is disconnected from the charger after the final discharge and must not be connected to the screwdriver during storage.

The duration of the power supply will be significantly extended due to this elementary procedure. Such batteries are stored for a very long time in a discharged state, without losing their properties. Naturally, you do not need to count on the possibility of eternal use of these batteries because the number of full discharge and charge cycles is limited.

New technologies

The battery for an Interskol screwdriver is also being developed on the basis of elements with a different chemical composition. Much longer than the "barrels" described above, hybrid batteries made of metal and nickel can last. The unequivocal advantage of such batteries is a significantly larger number of discharge and charge cycles.

There are still disadvantages

Self-discharge and "memory effect" are absent in such high-quality devices. The impossibility of operating the battery in low temperature conditions, as well as the high cost, are two significant drawbacks of this type of product. Do-it-yourself screwdriver battery repair can be carried out according to the scheme indicated at the beginning of the article. It will be necessary to completely replace the entire filling of the battery if it has been damaged as a result of exposure to low temperatures.

In many cases, the peculiarity of the battery assembly prevents its repair. Some models are quite easy to understand. Removing the battery components will be much more convenient due to the design of the case, the elements of which are fastened with screws.

Such models are easy to assemble, so they are easy to repair. Glued cases are much more difficult to disassemble. The procedure can be facilitated by preheating the battery parts.

Conclusion

A faulty screwdriver battery charger or the battery cells themselves are very easy to repair. The procedure will not seem too abstruse to anyone. Battery components may be removed.

Replacing non-working batteries of the battery pack with new ones can be done after opening the case. The charger also needs to be checked. The method of replacing battery components is only advisable if spare parts are available, because their purchase is often comparable in cost to a new battery.

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