We repair the battery for a screwdriver. Repair or restoration of the screwdriver battery

Screwdrivers are used in various conditions and their load levels are different. Therefore, they differ in their power, which directly depends on the battery. If an element breaks down, you need to be able to carry out prompt repairs with your own hands.

Battery types

By design features, batteries are distinguished in the form of sliders and clips.

But these are minor differences compared to battery types. Both slider and clip are used in different types batteries.

There are three types of screwdriver batteries:

1. Nickel - cadmium (Ni-Cd).
2. Nickel - metal hydride (Ni-Mh).
3. Lithium - ion (Li-Ion).

Lithium - polymer batteries (Li-Pol) are not manufactured for screwdrivers. The main areas of their application: smartphones, Cell Phones, tablets, laptops, radio-controlled devices, electric vehicles.

Nickel - cadmium batteries the cheapest, fast charging, have over a thousand charge cycles. Batteries are resistant to operation under low temperatures. But they have a memory effect. That is, you can charge them only after complete discharge, otherwise the capacity will fall. They have a high self-discharge current. They are made from toxic materials and are difficult to dispose of. These batteries are the most popular.

Nickel - metal hydride batteries more expensive, non-toxic, have a low memory effect. The self-discharge current is greater than nickel - cadmium. The capacity is higher, the charge cycle is more than five hundred. These batteries are less tolerant of high discharge rates. They are less suitable for maximizing the power of the tool. They need to be constantly recharged.

Lithium - ion batteries more expensive, more powerful, fast charging. They have no memory effect. Low self-discharge current. The voltage of the battery cells is greater, so their number is less. Therefore, the dimensions and weight of such batteries are less than that of nickel ones. But they cannot be completely discharged, otherwise after several such cycles you will have to buy a new one. To improve the quality of lithium-ion batteries, manufacturers install a microcircuit in the battery case or a screwdriver that controls the operation of the battery. A multi-level multi-stage protection is formed:

1. From high temperature.
2. From full charge. These batteries are afraid of a full discharge and cannot recover if the discharge is below the permissible norm.
3. From short circuit.
4. From overcharging, as an explosion may occur.
5. From overload currents.

The control board installed in the battery case is more efficient. When the battery is separate from the screwdriver and not in use, the microcircuit monitors its condition and opens the circuit in case of any problems. The battery is fully protected.

Overview of a lithium-ion battery with a chip

Battery problems

What can be a problem with batteries:

• flowing;
• not removed;
• decreased capacity;
• not charging;
• the charging and discharging time is reduced.

Nickel batteries can be recycled. And lithium is impossible, since lithium decomposes in them. Here you can only replace unusable batteries.

How to repair with your own hands.

Be patient and start repairing.

We disassemble the battery.

Disassemble the battery carefully. Do not use force to avoid damaging the case.

• Remove the battery from the screwdriver. If the buttons are stuck and it won't come off, unscrew the tool body screws and remove the top half. One of the buttons is free. Pull the battery towards you, slightly moving it in different directions, and it will also be removed. Once you have taken the battery apart, position the buttons so that they can be pressed easily into their grooves.
• The battery case consists of two parts and can be collapsible and non-collapsible. In the first case, unscrew all the screws and separate both parts.
• In the second case Bottom part the case is tightly planted on the top and glued. Therefore, to separate them, take a rubber mallet or a piece of wood such as a rolling pin and tap lightly on the seam around the case. If that doesn't work, use thin sharp knife. Insert it into the seam and carefully cut through the adhesive.
• Then knock again. Sometimes it happens that the battery is already almost dismantled, but in a certain place it stubbornly resists. Do not strike for a long time at one point, as you risk damaging the body. Just take a chisel or screwdriver and pry in the right place.
• When disconnecting parts of the case, the buttons may shoot, but this does not mean that they are broken. They need to be assembled and put into place. To take off upper part from the batteries, insert a screwdriver into any of the terminals and gently press the element. Pull the case up and it will come off.

Video: How to disassemble a screwdriver battery

Inside are several successively soldered elements. Such a cassette provides the necessary voltage and current characteristics for the battery. Some nickel batteries have a temperature sensor attached to the cells.

In lithium - ion batteries, everything is more complicated. There is a control board, and the elements are dressed in a protective case or film.

How to increase battery capacity.

A new battery must be fully charged before use. average temperature environment from 10 to 40 degrees. Chargers have indicator lights. When they show that the battery is charged, you must immediately turn off the process.

1. New nickel-cadmium batteries must be shaken before first use. Fully discharge and charge three times. The capacity will be maximum. If the instructions for the device say that the buildup should include more charge cycles, then follow these recommendations. During operation, fully discharge the battery before charging.
2. Nickel-metal hydride batteries have less memory effect, so they can be pumped once before first use.
3. Lithium-ion batteries do not need to be pumped. Simply charge them up to full capacity.

To discharge the battery, a load in the form of a 12 volt lamp is used. It is connected by crocodiles to the terminals. If the battery is disassembled, then to the terminals of the serial circuit of the batteries. The discharge process will take less than an hour.

Video: How to drain the battery

The second way to properly discharge is to use a "smart" charger like imax b6, which is very convenient for pumping batteries. In it, you can adjust the current and voltage parameters for charging and discharging the battery. Set the automatic cycling mode to build up the battery. That is, you do not need to constantly monitor the capacitance and voltage. The device will do it for you. Up to 5 cycles available. And at the end you will be able to see the values ​​of current and voltage after each cycle and analyze the result.

Video: Overview of the imax b6 charger

Diagnostics.

After fully charged, disassemble the battery. Inspect the elements for swelling and oxidation. Use a multimeter or tester to measure the voltage of all elements. Voltage limits for different batteries:

1. For nickel - cadmium 1.2 - 1.4 volts.
2. For nickel - metal hydride 1.2 - 1.4 volts.
3. For lithium - ion 3.6 - 3.8 volts.

Tester diagnostics.

The battery banks are wrapped in paper. Voltage is applied to each element. If all cells have normal voltage, discharge the battery by half the power. Measure the voltage again. Those elements in which the voltage has decreased by 0.5 - 0.7 volts compared to the average are subject to restoration or replacement. About such banks they say "flows".

Video: How to check battery status

Why is it not charging.

If the charger is OK, check the contacts between the battery and the charger. The charger contacts could be bent. This causes the battery to not charge. Disassemble the device and bend the terminals. The second reason may be a failed or soldered temperature sensor. It must be soldered or replaced with a new one.

Charges and discharges quickly.

When the contacts of the battery, charger, and tool are oxidized and dirty, the battery charges and discharges quickly. Wipe the contacts periodically.

Evaporation of the electrolyte.

The electrolyte boils away due to accelerated charging and overcharging. If the cells are not swollen and show operating voltage after a full charge, they can be restored without replacement. It is necessary to fill the empty volume with distilled water.

• After identifying defective cans, cut the connecting metal tape. Unsolder the elements.
• Take a punch with a thickness of no more than 1 millimeter. Where the jar has a minus, make a hole in the body.
• Pump out air up to 1 cubic centimeter and pour the same amount of water.
• Epoxy seal the elements and connect them to the circuit.

If this method does not help, then replace the banks with new ones.

Video: Adding distilled water

Replacement and soldering of batteries.

When you have carried out diagnostics and identified defective cans, you need to purchase their replacement. New elements must completely match in size and technical characteristics.

Video: Replacing cells in a battery

How to convert a screwdriver to a lithium-ion battery.

Many owners of a screwdriver with a nickel - cadmium battery have encountered such a problem that when you need to use it, the battery is always discharged. And constant charging kills it due to the memory effect. Therefore, they remake such a battery for lithium - ion.

The source of lithium batteries can be old battery from a laptop or you can buy new ones. Notebook and new banks are unprotected. You cannot use them without protection, because you will not be able to charge them and control the discharge. And when reloading, they will safely die. It is allowed to connect in parallel exactly the same batteries, then they will work as one. Get a series battery protection module that monitors and takes care of each cell individually. Monitors voltage and current, provides short circuit protection. Such modules are available for one, two, three and four batteries.

Battery compartments for different number of batteries

To increase the capacity, you can add elements connected in parallel. Solder lithium batteries it is forbidden. They can be put in holders and solder contacts of holders. Or connect with nickel-plated tape and resistance welding, which allows you to quickly heat up a very small area, and the battery will not suffer.

For contact welding we will need:

1. Powerful high current source. It can be a converted microwave transformer or a lead battery.
2. A thick copper stranded wire, at the ends of which single-core copper contacts are fixed at a distance of four millimeters.
3. Metal tape. It is inexpensive, and you can connect it with about five assemblies. This is much more profitable than holders.

Put the tape on the battery, press the contacts in the place of welding. Switch on the current for a short time. On a battery, this can be done by making a sharp short contact with the terminal. A button is placed at the input of the primary winding of the transformer. For ease of welding, connect the elements with glue. Cook according to the scheme, bending small pieces to attach the measuring wires for the module. "+" and "-" of the entire assembly solder to the module.

Connection diagrams with the controller for two, three and four elements

The output from the battery must be done with thick wires. If you don't have heat shrink tubing large diameter, wrap everything with electrical tape. The resulting battery will be very compact and neat.

Heat-shrink tubing.

Take the old battery and take it apart. Leave only a protective thermal sensor in it, since the charger will not work without it. Solder a new battery, and fill the free space with foam or cardboard.

Video: Converting a battery to lithium - ion

Now the most important thing. How to charge such an assembly? Need to charge with voltage equal to the sum maximum allowable voltage on each battery. The recommended charge current should be half the capacity of one battery. Such a custom source is a complex charger like the Chinese imax B6. In it, you can set the number of batteries and the desired charge current.

Restoration and repair

The main methods for the recovery of nickel batteries:

Sealing (compression).

Eliminate the memory effect.

Addition of distilled water instead of the boiled off electrolyte.

You can squeeze the jar with pliers gently and evenly over the entire surface. Be careful not to damage the contacts. The electrolyte will become denser and its storage capacity will be restored.

The memory effect is easily detected. Once fully charged, the battery drains quickly during use. A few hours later it works again. To erase the memory effect, an electrical impulse of a larger capacity than usual is applied to the battery.

Video: Flashing a battery with a higher capacity and voltage to erase the memory effect

In lithium - ion batteries, the cells are not recoverable. They are replaced by workers. It is necessary to unsolder the control board, and replace and assemble the non-working elements in the same way as when converting the battery to lithium-ion.

Video: How to replace lithium-ion battery cells

If the lithium-ion battery does not charge from the native charger, try using the imax b6. Set the mode to "nimh" and watch the voltage carefully. When it reaches 3 volts, switch to "liion" mode. Keep charging at normal mode. Such a process should be done in a short time. And be sure to control the voltage. If you leave the battery on charge and forget about it, it will overcharge and fail. If this does not help, then look for defective batteries and change them.

Video: Charging a lithium-ion battery from imax b6

How to store

Before use, be sure to read the instructions for the device.

Nickel - cadmium batteries before storage, discharge, but not completely, but so that the screwdriver does not work at full strength. After a long period of storage, shake the barateu in the same way as before the first use.

Video: Advantages, disadvantages, operation and storage of nickel-cadmium batteries

Nickel - metal hydride batteries fully charge before storage. If not used for more than one month, recharge periodically. After long-term storage, do not charge for a day.

Lithium - ion batteries can be charged at any time. They have the lowest self-discharge current. The main thing is not to discharge them completely. If during operation the tool stops working at full strength, do not risk it. Charge the battery.

As you can see, battery repair is not that difficult. If you correctly diagnose, then you can independently repair all types of batteries.

Application cordless screwdriver does not depend on the presence of a nearby power supply, which increases the comfort of working with the tool. Screwdrivers are intended for professional and domestic use. Accordingly, the batteries for them differ in quality, price and capacity. Lately manufacturers produce rechargeable batteries (batteries) with sufficient power for the tool with a relatively small size of the power source.

The battery for a screwdriver is a set of elements (cans) connected in series at the bottom of the tool body. The supply voltage range for various models of screwdrivers is 9-18 V. EMF professional tool can reach 36 V. The higher the voltage of the supply element, the more powerful the tool. The more capacity in each battery, the more time it can work without recharging. The battery capacity of household screwdrivers is within 2.7 A / h.

Battery types

How does it work rechargeable battery, is known to everyone from the school physics course. The power supply consists of 3 main elements: anode, cathode and electrolyte. When charging the device with chemical processes in the electrolyte there is an increase in the potential difference between the electrodes.

Most often, nickel-cadmium batteries (Ni-Cd) are used to power screwdrivers. Devices of this type have the following features:

1. They differ in low cost and rather big capacity. Designed for 1000-3000 charges. Battery life varies by model, usage pattern, and charging pattern.
2. Reduces the duration of operation of this type of device having a memory effect. If the cells are charged until they are completely discharged, the capacitive qualities of the battery deteriorate over time. In this case, crystals form on the contacts of the device, which also reduces the capacitance of the device.
3. Another disadvantage of a nickel-cadmium battery for a screwdriver is the toxicity of the materials used for its manufacture. chemical substances. In European countries, the use of this type of battery was abandoned.

If a tool with a Ni-Cd power supply is used infrequently, then over time the initial specifications can be reduced by 3 times. At regular work with a screwdriver, the battery can last up to 2-3 years. At the same time, it must be operated at an ambient temperature of at least 0 ° C and in the absence of high humidity.

Nickel-metal hydride (Ni-MH) batteries for a screwdriver differ from the previous type of battery in the following technical characteristics:

1. During their manufacture, operation and after disposal, there is no danger to human health.
2. The memory effect they exhibit is much less than that of Ni-Cd batteries.
3. The disadvantages of devices of this type include rapid self-discharge. When left on long-term storage they must be charged, and if the battery has not been used for a month, then it should be charged again.
4. The device is sensitive to work with maximum load. Rapid discharge reduces its capacitive properties over time.

The new generation of power cells include lithium-ion batteries (Li-Ion). You can recharge them at any time, regardless of the degree of discharge.

The devices are environmentally friendly, but it is not advisable to work with a screwdriver with Li-Ion batteries at low temperatures.

Tools with such a power source are not yet very common only because of high price for products.

The most expensive part of a screwdriver is its battery. It makes up about 70% of the total cost of the instrument. Therefore, if a battery malfunction occurs, then acquiring a new screwdriver or battery for it can be a serious hole in the budget. If the battery is out of order, then with certain knowledge, you can repair the screwdriver with your own hands.

Types of batteries

First of all, you need to figure out what type of battery you have to repair. To do this, you need to know the features of each type. The structure of these elements is similar in models of tools made in different countries. When disassembled, this part consists of various elements connected in series. Such a connection means that the potential of all elements is added up. The total voltage across the battery contacts is the sum of all the cells.

As a rule, all elements have standard sizes and characteristics. Their difference lies in the capacity, the unit of which is A / h. The capacity is indicated on each typesetting element (they are also called "banks").

"Banks" can be of various types:

• lithium-ion (Li-Ion);
• nickel metal hydride (Ni-MH);
• nickel-cadmium (Ni-Cd).

The first type has a voltage of 3.6 V, and the other 2 - 1.2 V. Each of the types has its own advantages and disadvantages. The advantages of nickel-cadmium cells are as follows:

• low cost and wide distribution;
• insensitive to low temperatures;
• retain their characteristics when stored in a discharged state.

The disadvantages of this type of "cans" are as follows:

• production is accompanied by the release of toxic substances, therefore they are produced only in a few countries;
• self-discharge;
• memory effect;
• low capacity;
• quickly fail due to the small number of charge / discharge cycles.

Nickel-metal hydride cells have the following advantages:

• environmentally safe production, which makes it possible to buy parts produced in those countries with high quality standards;
• the memory effect is weakly expressed;
• relatively high capacity;
• low self-discharge;
• many charge/discharge cycles.

Nickel-metal hydride parts also have disadvantages:

• high price;
• long-term storage in a discharged state adversely affects the performance;
• fail quickly at low temperatures.

Lithium-ion "banks" are attractive for the following properties:

• there is no memory effect;
• very low self-discharge;
• high capacity;
• several times more charge / discharge cycles than other parts;
• fewer parts are required, which reduces the weight of the instruments.

You can determine a faulty battery with a multimeter, which will show which of the "cans" is faulty.

The disadvantages include:

• very high price;
• since lithium decomposes, after 3 years of operation, the capacity is significantly reduced.

The accumulator batteries are enclosed in a case. The housing has 4 pins:

1. For discharge / charge 2 power contacts - "+" and "-".
2. Top control connected via thermistor. The thermistor (or thermal sensor) helps protect the battery from overheating when charging. If the temperature rises too high, the charge current is limited or switched off.
3. Service contact connected through a resistance of 9 kOhm. It is designed to equalize the charge on all elements of complex charging stations. Such stations are used only in industrial tools and devices.

Knowledge of the design of the screwdriver battery is necessary to carry out its repair.

Back to index

How to detect a breakdown?

It is possible to repair the battery for a screwdriver only if the battery malfunction is accurately determined. The entire circuit will be faulty if at least 1 element fails. Therefore, it is necessary to determine the location of the breakdown.

In order to repair the battery, you need to use a "donor", in which some of the elements are working, or purchase new "banks".

You can determine which element is out of order using a multimeter and a 12 V lamp. You need to put the battery on charge and wait until it is fully charged. Next, the case must be disassembled and the voltage of each circuit element must be measured. All "banks", the voltage of which is lower than the nominal, must be marked.

Further, the battery is assembled and works until the moment when its power begins to noticeably drop. After that, the case is disassembled again and the voltage of the circuit elements is measured again. Voltage sag on the marked elements is the most noticeable. If the voltage difference various elements is from 0.5 V, and even if this element is still working, it will become unusable soon enough. This technique allows you to determine which elements need to be repaired or replaced.

12 V or 13 V screwdrivers can be diagnosed more than simple method. A fully charged battery must be disassembled and connected to a 12 V lamp to the “+” and “-” contacts. This will create a load at which the battery will be discharged. After that, measurements are taken to determine the sections of the circuit where the voltage has dropped the most.

After the faulty chain links are found, you can start repairing the screwdriver battery. This work can be done in 2 ways. The functionality of defective elements can be restored or replaced with new ones.

Almost every battery in a power tool is the most expensive part of it. A screwdriver is no exception, because a replaceable battery can be from 30% of the total cost of a tool. After discharging the device, you need to purchase a new screwdriver, but to save money, there is another option - restoration, which will extend its service life.

Screwdriver battery drains quickly

The problem with the rapid self-discharge of the battery is quite common. It consists in fast charging, which takes place in 20 minutes and the same short work.

This situation may be the result of incorrect operation of the thermal sensor located in the removable battery. This temperature sensor may not be installed in the original way. You must return it to the place of purchase.

If the battery begins to discharge quickly after prolonged uninterrupted use, which could happen after a fall, you need to take it to repair.

Battery not charging

Screwdriver after prolonged use, it happens, fails. Its working element may stop charging, which will lead to the impossibility of performing the functional abilities of the tool, the tool, roughly speaking, will “die”.

In order to extend the life of the tool so that you do not have to remove it from the visibility zone, you can try three methods in turn. Each subsequent one is considered more complex and costly. They consist in:

• restoration and increase in capacity after its reversible loss (memory effect);
• adding distilled water to the electrolyte;
• replacing some or all of the battery packs.

Screwdriver battery life

The battery can last about three to four years with proper use and storage. In practice, this period is sometimes reduced to two years. It is very expensive to change the tool all the time, so it is better to choose right away best option for one purpose or another.

There are 3 different types batteries:

1. Nickel-cadmium. The most affordable, but short-lived, especially with frequent work in cold weather conditions.
2. Nickel metal hydride. A small device that does not have a long service life.
3. Lithium-ion. The most popular ones are capable of not being discharged for a long time, but have a higher cost than the above options.

Regardless of battery type, battery life depends on the number of charges used and how it is stored. That is, the more the tool works, the faster it discharges. At the same time, “simple” operation negatively affects the period of use, especially if you store the tool in the state when it sat down.

How to restore the battery of a screwdriver at home

Is it possible to reanimate all types of batteries? Better repair nickel-cadmium blocks, which are available in almost all modern screwdrivers, lend themselves.

For the recovery process, you need to understand the basics of electricity. That is, to have school knowledge about the operation of batteries.

For work you will need tools and materials:

• screwdriver;
• tester;
• soldering iron;
• tin (with low-corrosion flux).

A donor is needed to resuscitate the battery. In the configuration of the screwdriver, it may be available, or you need to find it yourself, for example, by removing it from another old device.

To start the operation, it is necessary to fully charge (about 6 hours) both batteries, swing it. After that, remove the plastic cover from the part to be restored with a screwdriver. This procedure must be done carefully so as not to damage the latches. Otherwise, for subsequent assembly, you will need glue, like "Moment".

Recovery of nickel-cadmium batteries for screwdrivers

The ni cd battery device is manufactured using the same technology, so any battery can be made a donor of this type.

Such devices are individual components- blocks, with a nominal voltage of 1.2 V and an energy capacity of 1200–1500 MA / h. They are found in Interskol screwdrivers. Each block affects the power, that is, with its value of 12 V, the number of blocks is 10 pieces, 14.4 V - 12, etc. After changing the battery, the power may drop for the first time of operation, but then everything will be restored.

18 volt screwdriver battery recovery

18 V is a common power that corresponds to the presence of 15 blocks. As a donor, you need to choose an electrical appliance with a voltage of 14.5 V, that is, a 12 V car battery will not work.

How to restore and start a lithium-ion battery

For these types of batteries, you will need to remember where the plus, minus and charging contacts are located. The voltage control board, located on the batteries, most often fails, or rather, their stabilizers and protective diodes.

The voltage at the battery output is checked, if the value is much less than normal, resuscitation is performed.

The second life of batteries in screwdrivers Bosch, Hitachi, Makita

The featured brands come with a lithium-ion battery. Reviving them requires a soldering iron and sleight of hand, because if you do everything slowly, the service life may decrease, or the battery will explode altogether.

All broken or frayed wires inside the battery must be isolated, for example, with electrical tape or replaced with new ones in advance.

For restoration, torn off metal elements are soldered - tapes that can be taken in old blocks.

For assembly, it is necessary to return the cardboard gasket between the blocks and the board to its place. This is required to prevent shorting. Then the contacts are isolated.

Battery life is relatively short, 5 years on average. After a set period, the battery abruptly stops working. In such a situation, it is not always possible to quickly acquire a new power supply, so home master you have to solve the problem of how to restore the battery of a screwdriver, at least for a short time. In some cases, after a successful recovery, the batteries work normally for quite a long time.

Structural elements of a screwdriver

A screwdriver is considered indispensable universal tool. Modern market screwdrivers presented big amount battery-equipped models. Despite the variety of brands and modifications, all batteries have the same structure and differ only slightly from each other.

Each of them consists of separate elements connected in series with each other. All of them are made according to standard sizes and have the same voltage level. Separate types elements differ only in capacity, measured in A / h and indicated in the marking.

There are 4 contacts in the body of the tool that perform various functions. Including two are power, designed for charging and discharging. In addition, in the upper part there is a control contact included in the circuit along with a special thermal sensor. It protects the battery, turns off the charging current and limits it to the set value by changing the temperature regime.

A fourth contact is located separately, connected together with the resistance. It is required when using charging stations increased complexity capable of equalizing the charges of all battery cells. Such stations are rarely used in everyday life due to their high cost. A conventional 12 volt screwdriver does not require such stations.

One of the reasons for the failure of a screwdriver is a battery malfunction, that is, its individual element. In such cases, when connected in series, the entire circuit fails. Therefore, it is very important to accurately determine the faulty place. As a rule, this happens after the expiration of the established period of operation. This problem can be resolved in two ways: purchasing a new battery or repairing and refurbishing an old battery.

What batteries are used in screwdrivers

Proper diagnosis involves knowledge of the main types of batteries used in screwdrivers, and the design features of each of them. Each battery consists of mini-batteries connected in series in a single chain. Depending on the material of manufacture, they are nickel-cadmium (Ni-Cd), nickel-metal hydride (Ni-MH) and lithium.

The first option - Ni-Cd is the most widely used. In these batteries, each cell has a voltage of 1.2 volts, and a total of 12 volts is obtained with a capacity of 12,000 mAh. They differ from lithium ones in the possibility of recovery, since they have a known memory effect, which is a reversible loss of capacity.

In connection with design features batteries, not all methods are suitable for their recovery. For example, lithium cells cannot be restored using Imax B6 charging, since lithium gradually decomposes, loses its qualities and does not hold 18 volts. The same method is not always suitable for Ni-Cd batteries, since in some cases the electrolyte can completely boil away in them. However, there are plenty of recovery options.

Different types of batteries also differ in their own operating voltage of the cells. A similar difference is due to the materials used to make a particular battery. This factor also affects the capacity, which ensures long-term operation of the tool without additional charging. Therefore, during the initial opening of the case, first of all, the type of elements placed inside is determined. The fact is that it is not allowed to replace lithium mini-batteries with nickel-cadmium ones, since their operating voltages differ significantly. Accordingly, the methods of repair and restoration will differ.

To repair the battery, you will need measuring instruments- for 2 A, for 2 and 15 V, a tester, and a milliammeter. Manipulations with the body are performed with a screwdriver, scissors and pliers. A magnifying glass may be needed to detect defects.

While solving the problem of whether it is possible to repair the battery, a search is made for a faulty element and its further replacement. Used to check standard scheme, and on the basis of the data obtained, the state of individual parts is analyzed. It should be remembered that not only mini-batteries, but also the terminals of the screwdriver itself may be faulty.

Determination of the causes begins with voltage measurements with a tester on each individual battery. All non-working elements are marked and separated from serviceable ones. If the battery is rapidly discharging, do not immediately disassemble it. First, you can try to restore the battery capacity of the screwdriver. For this purpose, the battery is fully charged and deeply discharged over several cycles. In most cases, the capacity is restored almost completely.

Often the screwdriver stops working due to the failure of the terminals. During operation, they gradually unbend, as a result, the contact is broken and the battery is not fully charged. To repair the charger, you must first disassemble it, and then carefully bend each terminal. After that, it is necessary to check the quality of charging using measuring instruments.

If the measures taken did not help, you just need to replace the defective part. If a specific cause of a malfunction is found, it is recommended to use the recovery methods below.

How to eliminate the memory effect

When a battery is under-charged and then discharged very frequently, it has a so-called memory effect. That is, the battery gradually, as it were, remembers the minimum limit of charging and discharging, as a result, its capacity is not fully used and gradually decreases more and more.

This problem is typical mainly for nickel-cadmium batteries and to a lesser extent affects nickel-metal hydride. In any case, you need to restore the battery capacity. The memory effect does not apply to lithium-ion batteries at all.

In order to solve the problem of whether the cell can be repaired, it is recommended to fully discharge and charge the battery using a 12 volt light bulb. The positive and negative wires are soldered to it, which are connected to the battery contacts. This procedure is repeated five times or more.

How to top up with distilled water

Distilled water only evaporates from nickel-cadmium batteries when they overheat during operation. Therefore, to eliminate the problem and restore their functions, water must be added.

This procedure is performed in the following sequence:

• After disassembling the battery, mini-batteries will be found inside. Their number may vary, depending on the brand of the instrument. A failed element is determined by a multimeter. In a good battery, the voltage is 1-1.3 V. If this indicator is lower, then the element is faulty and needs to be repaired.
• Next, the defective parts are carefully removed without destroying the connecting plates. You will need them later for reassembly.
• A hole of no more than 1 mm is drilled in the side part. It is not located in the middle, but closer to the bottom or top of the battery. You need to drill only the wall, without going deep into the element.
• Fill the syringe with distilled water. The needle is inserted into the hole and through it the battery is completely filled with water. After that, she should stand in this position for at least a day.
• In a day special device The battery is charged and then left charged for another 7 days.
• A week later, the capacity and voltage are checked again, and if it has not fallen, then the hole in the case is sealed or sealed with silicone.

After all the manipulations, the batteries are assembled into one and inserted into the battery case. The connecting plates are soldered or joined by spot welding. The whole battery is then checked once again for proper operation, after which it is completely discharged with small loads. The charging and discharging process is performed at least 3 times.

Replacing old batteries

In this way, you can repair the battery of any screwdriver. The repair procedure itself is not particularly difficult and begins with disassembling the battery. Using a multimeter, faulty elements are determined, in which the voltage will be below normal. Then they are carefully removed and replaced with exactly the same mini-batteries.

New parts are installed in their places and connected by existing plates. Soldering is used for connection or spot welding. In this case, you need to ensure that the battery does not overheat. Therefore, the work must be done carefully and quickly using flux or rosin.

Gas release from the battery

This repair method applies to elements lithium-ion batteries. During the period of use, they overheat, as a result of which electrolyte evaporates from some batteries. Because of this, gases accumulate inside the battery, causing swelling, accompanied by a bending of the plate. After that, you have to restore the battery of the screwdriver.

The solution to this problem is carried out in the following order:

• Disassembly of the battery and search for a defective battery with a multimeter. Usually in such elements there is no voltage at all.
• After that, the battery is removed outside and gas is released from it. In the first case, you will need some kind of flat tool, curved at the end. It is brought under the positive contact and the swollen plate is gently pressed down. The gas finds its own way, making a hole and going out. In this case, you restore performance only for a short time, because the electrolyte will completely evaporate through the hole and the battery will stop working again.
• In the second case, the positive contact is disconnected using wire cutters, after which it is slightly bent, but not completely cut off. After that, an awl is inserted under the curved plate and gradually pushed inward. That is, the plate is separated from the edge of the battery and the gas comes out. After that, it is inserted into its place, and the hole is closed up the most convenient way. It remains only to solder the contact that was disconnected at the very beginning.