Battery conversion of Black Decker Cordless Screwdriver

How to repair the battery of an electric screwdriver and its faults

Cordless electric screwdriver, can always be useful in the economy, but over time, its power source suddenly refuses to work. Buying a new electric screwdriver is expensive. Its price consists of around 70% of the cost of the battery. And as models often change, it is quite difficult to find a new battery for this particular tool. So the question arises as to what to do next. Should I buy an electric screwdriver or look for a similar battery?? But you can solve this problem by repairing the battery yourself, prolonging its life for several more years.

It is worth noting that batteries for almost all brands of screwdrivers, regardless of what country they are manufactured, have a similar device. But each type of battery has its own specific characteristics.

If you disassemble the battery, you can see that its device consists of individual cells connected in a common circuit in series. Many people should remember even from their school years that the charging elements connected in series in one electrical circuit increases the total power.

Battery types

Has a fairly high capacity, so one full charge can be enough for 1500 cycles. But it needs constant charging. Also this type of battery is not recommended when the air temperature is low.

Practically the cheapest batteries with a rated voltage of 12.5 V. They have a small capacity, so the discharge occurs fairly quickly. But they cannot be recharged. Therefore, in order to prolong the life of these batteries, it is recommended that they be fully discharged before recharging. The advantage of nickel-cadmium batteries is that they recharge quickly, operate for a long time with proper maintenance and work well at low temperatures.

They have a high capacity and recharge quickly. Can be freely recharged at any time, but must not be completely discharged. Also not recommended for use at low temperatures. Can not withstand long storage without periodic discharging and recharging (after a certain period of storage is recommended to give the battery a load).

There are two pins on the battery case which are identified as plus/minus pins for electric screwdriver power and two pins for charging. A thermistor is connected to one of the charging contacts to protect the battery from overheating during charging. The thermistor completely shuts down or reduces the charging current strength when the batteries reach a temperature of 50-60 degrees. Batteries often heat up during intensive, so-called “fast” charging.

Causes of failure

Battery failure is possible for a variety of reasons. Therefore, before you try to repair it, you should make sure that this action is advisable. It may be that the labor and expense incurred to repair it will cost more than a new purchase.

For example, a frequent source of problems, due to which the battery stops working is its long service life. For some types of batteries, after a certain period of time, the capacity of the batteries decreases and they quickly discharge during operation. Naturally, in this case, most likely, it will not be possible to restore their performance.

There are also some other malfunctions:

Non-standard application

Screwdrivers often find quite unexpected uses. For example, some resourceful people use an electric screwdriver to clean sewage pipes and clogged drain holes. To do this, they fasten a small rope or a wire bent in half into the clamping chuck. Such a device is slipped into a drain hole, after which at low speeds the clogged pipe is cleaned.

They use the electric screwdriver to mix mortars or even peel potatoes. It is also used to compactly coil up wire, wires and large sections of rope for storage. This is how a block of wood is attached to the holder with a screwed-in self-tapping screw, and then wire or rope can be wound at low speed. The same principle applies to making springs in the home.

Unusual application

Screwdrivers often find quite unexpected uses. For example, some resourceful people use an electric screwdriver to clean sewer pipes and clogged drain holes. To do this, they attach a small rope or a wire bent in half to the clamping chuck. Such a device is slipped into the drain hole, after which at low speed the clogged pipe is cleaned.

Electric screwdriver to mix mortars or even peel potatoes. It can also be used to compactly coil wire, wires, and large sections of rope for storage. So with a screwed-in self-tapping screw, a wooden bar is attached to the chuck, after which a wire or rope begins to wind at low speed. The same principle applies when making a spring in the home.

How to convert a cordless electric screwdriver to 220 volt mains: step by step instructions video

The value of an electric screwdriver as a household or construction tool is most often in its portability. However, due to some circumstances, sometimes you have to give up portability in favor of functionality. It is a question of converting a cordless electric screwdriver into a tool powered by the mains. This process has a number of subtleties that it is advisable to observe.

Device design

The screwdriver consists of several basic elements:

  • A cylindrical electric motor powered by current. There are permanent magnets inside the body, which allow the structure to gain sufficient torque. They are also handy when repairs are needed. The motor shaft contains a planetary gear.
  • Torque limiter. Necessary to limit the amplification when working with a screwdriver. Transmits the torque through hinges pressed by an internal spring.
  • Planetary Gearbox. Named after the solar system that it resembles when being assembled. Located in a separate housing and composed of several gears and other parts. Acts as a force regulator. In the drill mode works harder.
  • Speed regulator with reverse. It is activated by reversing the polarity of the connection.
  • The battery of a device. Consists of several separate power cells in one casing. Voltages range from 9 to 25V in different devices.

Exploded appliance Source stroy-podskazka.The battery has replacement or repair options in the event of a battery malfunction. It is usually expensive to change such batteries, because in a cheap device the replacement will be about equal to the full cost of a screwdriver. Repair is not always possible, in addition, as in the first variant, its cost will be close to the full price of the device. But there is also a third option, such as to remake the screwdriver to work from the mains, which will allow you to use the tool further without much cost and effort.

Is it really worth redoing?

Without batteries, the screwdriver becomes a piece of hardware. When the batteries stop holding a charge, you have to look for new batteries. First, it is expensive. The price of batteries accounts for up to 80% of the cost of a screwdriver, so it is more efficient to buy a new tool. Secondly, batteries are not always available, for example, if the model is discontinued. Third, the diligent owner seeks to use all opportunities to save money.

Converting a cordless screwdriver to work from the electric network is a good way out. What it gives:

The disadvantage of the redesign is the dependence on the socket and the length of the mains cable.

Attention! Work at heights above two meters with a converted screwdriver is not permissible.

Battery composition

There are almost no design differences from the batteries of different screwdrivers, because the system is similar everywhere, and may differ in appearance or contacts. The casing consists of cells connected in series, the number of cells is limited by the voltage of each cell and the battery as a whole. For example, using the most popular rechargeable models. Nickel cadmium batteries, you will need about 10-12 pieces to fully power the device. Each battery has a capacity specified in ampere hours. The higher it is, the longer the device will work without recharging at a certain power.

Battery in disassembly Source amperof.Ru

See also: Directory of companies that specialize in electrical work and related equipment

General recommendations

All listed methods include one unifying step. Disassembly of the supply module housing. If the frame is attached to the bolts, then it is not a problem, mount on the glue requires careful opening of the seam by tapping on the gap with a hammer, buried in it a knife.

During installation observe the direction of voltage. It must not flow to the battery. Therefore the module is mounted in parallel to the supplying contacts, in the plus line is built in a diode illuminator for a certain power.

Summary: the question “can an electric screwdriver work from a battery charger” has a positive answer, and several solutions, but requires caution, some scientific knowledge and skill.

Makita charger 193864-0, 7.2V-14,4V Ni-Cd, Ni-Mh green Price: 1750 P

Tool charger MILWAUKEE 7.2V-24V Ni-Cd, Ni-Mh black Price: 3530 P

Tool charger Bosch 7.2V-24V Ni-Cd, Ni-Mh black Price: 3570 P

Tool charger for DeWALT 7.2V-18V Ni-Cd, Ni-Mh black Price: 3570 P

The absence or total failure of a battery charger with an electric screwdriver stops all planned works. But by applying ingenuity, some available tools, the question of t.

An electric screwdriver with self-contained power supply is definitely one of the best inventions of mankind, and it makes life much easier for almost all mu.

Battery types

Electric screwdrivers use batteries with different voltages and compositions. They all have advantages and disadvantages in operation.

As mentioned above, the most popular batteries are nickel-cadmium. Perfectly preserved in the discharged state and have an acceptable price. High degree of self-discharge and low capacity are among the drawbacks. Such batteries also have a small number of cycles of full charge and discharge.

Quality repair batteries screwdrivers in Krasnodar

Electric screwdriver. A popular device in the household in some ways it will replace the drill, but it is not as versatile. Repair the battery electric screwdriver itself is difficult, it is better to entrust the job to professionals. In Krasnodar, if it breaks down, you can turn to a service that repairs any model of this tool, both Russian manufacturer (Interskol, Zubr), and foreign (Bosch, DWT, Hitachi, Makita and others).

Cases when the repair of the battery is justified

The price of such a device consists of 70% of the cost of its battery, so when this unit fails, there is a natural question about the purchase of another device. But it is not always justified, in the following cases, repairing the device will be cheaper than buying a new one:

  • The old model is made by a reliable company;
  • The habit and convenience of working with a proven appliance;
  • The electric screwdriver used is expensive and there is no money to buy a similar one;
  • It has a lithium battery.
  • The last argument in favor of restoring the old device is the strongest.

Types of batteries

The feasibility of repair depends on the frequency of use of the electric screwdriver and the type of storage unit, which comes in:

  • Nickel-cadmium. Cheap kind with a capacious capacity, but it is toxic and requires special disposal.
  • Nickel-metal hydride. It is not as dangerous as the previous type, but has a high self-discharge rate.
  • Lithium-ion. Portable device of the new generation, but with one disadvantage. It reacts to temperature fluctuations.
  • Lithium polymer. Compact in appearance, it is an improved copy of the previous variety.

If the electric screwdriver has the last two types of batteries and it is used constantly, it is worth coming to us for help and restore the work of this device.

Replacing the batteries in an electric screwdriver

Sometimes you do not need to replace the battery, you can only repack it with new cells and it will work, remaining in the old case. Reviews of people who have encountered such a problem, using the example of the device firm Bosch 12V, say that the cost of repair will be 4 times cheaper than buying a new construction device. Reinstall the battery. The solution for those who have an old battery in the device, which is no longer in production. But it is possible if the battery has been stored in a charged condition: 70% of the usual values of 12-18 volts.When contacting a service technician, you can immediately get an option to fix the problem. The company will provide a competent specialist, who even during the phone conversation will determine the cause of failure of an electric screwdriver. He will fix it as soon as possible, and the service will provide an official warranty. Replace batteries for screwdrivers master can quickly, we always have the right models.

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Installing other types of cells

Some screwdriver owners want to change the nickel-cadmium battery banks for lithium-ion to get all the advantages of the latter.

But to do this you need to do a lot of work and spend a lot of money which does not seem to make sense. It’s easier to just buy a new battery.

See for yourself. To install the lithium-ion cells you will also need the controller board that will cost a pretty penny. Plus the skills of soldering will be more solid. Just soldering banks to each other is less difficult than then correctly connect them to the controller, and even without damaging it.

But if a person wants to mess around and is confident, he can try it.

Checking under load

This means that we will check how long the battery of an electric screwdriver is fully discharged if an additional load, such as a light bulb, is connected to it.

The load level should be chosen based on the capacity of the battery. If this is not listed in the instruction manual, it must be calculated yourself. This will be half the current drawn by the battery during operation multiplied by the U of the power supply. Usually it is between 35 and 40 watts, which means that you can load either a car headlight with 35 watts or a 12-volt bulb.

To read the battery, you need to connect the lamp with an ammeter and read the readings with a voltmeter. The connection time is two to three minutes, after which we measure the U. If it is less than 12.4 volts, some “bank” is definitely out of order. Also a malfunction of the battery can be indicated by a significant decrease in the brightness of the light bulb. If it quickly goes out in two or three minutes, the battery is clearly not good, and its capacity is very low.

A rechargeable battery with a locking button

Since electric screwdrivers can be cordless or corded, they have different power systems. The cordless electric screwdriver has a built-in rechargeable battery, which is a device with built-in external contacts to transmit electricity. The main element of the battery is its power units connected in series. Otherwise they are called cans Sample in the photo.

It also has a thermostat that protects the battery from overheating while charging. The battery is a removable device, because when the resource is depleted, it must be replaced. The battery is attached to the screwdriver by a fixing button, which in some models is on the side and in others. On the front. Contact plates that connect to the battery and provide power depart from the handle.

Types of batteries

How a rechargeable battery works is familiar from high school physics. A power supply consists of 3 basic elements: the anode, the cathode and the electrolyte. When charging the device due to chemical processes in the electrolyte there is an increase in the potential difference between the electrodes.

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

  • They are inexpensive and have a large enough capacity. Designed for 1000-3000 charges. The life of the battery depends on its model, adherence to the mode of use and charging.
  • The possession of the memory effect reduces the duration of operation of this type of device. If you charge the battery until it is completely discharged, the capacitance of the battery will eventually deteriorate. In this case, crystals will form on the contacts of the device, which also reduces the capacitance of the device.
  • Another disadvantage of the nickel cadmium battery for an electric screwdriver is the toxicity of the chemicals used in its manufacture. The use of this type of battery has been abandoned in European countries.

If a tool with an Ni-Cd power source is used infrequently, over time the original specifications can be reduced by up to 3 times. The battery may last up to 2 or 3 years with regular use of a screwdriver. In this case, it should be operated at ambient temperatures not lower than 0 ° C and in the absence of high humidity.

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

  • There is no danger to human health in their manufacture, operation, and after disposal.
  • They have a much lower memory effect than Ni-Cd batteries.
  • The disadvantages of devices of this type include rapid self-discharge. They must be recharged when left for long periods of storage, and if the battery has not been used for a month, it must be recharged.
  • The device is sensitive to work at maximum load. Rapid discharge over time reduces its capacitive properties.

Lithium Battery Schematic of an Electric Screwdriver.

The power elements of the new generation include lithium-ion batteries (Li-Ion). They can be recharged at any time, regardless of the degree of discharge.

battery, electric, screwdriver, cordless, consists

The devices are environmentally friendly, but it is not advisable to operate an electric screwdriver with Li-Ion batteries at negative temperatures.

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

Repair of screwdriver battery packs

In some cases, screwdriver battery banks can be repaired. This applies only to nickel-cadmium batteries, because neither lithium-ion nor lithium-polymer cells can be regenerated. The reason is the chemical instability of the lithium compounds which decompose with time.

It happens in the following way. Over time, the amount of energy required to move the electrolyte ions in the lithium oxide environment increases. The reason is that the crystal structure of the cathode changes with the increasing number of charge/discharge cycles, but the release energy of the ions increases. As a result, the amount of free lithium ions decreases with each cycle, and the charge of the can for the same duration of the charging process will be less.

In addition, the charging is adversely affected by corrosion, peeling of the graphite plates that make up the anode, etc.

Repair of cans of non-warranty tool battery begins with the replacement of control circuit. If charging is normal with the new circuit, and the banks “sit down” during the operation of the screwdriver as they should be new, then the goal has been achieved.

At the same time the replacement of the control circuit is a cardinal method. It should be used only if other, simpler procedures of the banks resuscitation did not lead to the desired result. Therefore, it is worth trying one of the following options:

  • Compress the defective can in any way. This can be done with a pair of pliers, evenly over the entire outer surface, trying not to snag the places of contact pins. The electrolyte inside the can will compact and its storage capacity will be restored, although for a shorter period of time;
  • Give to the battery an electrical impulse of much greater power, both in terms of current and voltage. In doing so, the memory effect is knocked out. For this purpose, you should connect a capacitor with a capacity of up to 7000 7500 mF to the charged battery as an external load, which must be pre-charged to the potential difference of 18 20 V. The residual voltage at the bank after discharge should be at least 0.60.7 V.

Cordless Screwdriver battery replacement/upgrade

Any of the above methods can prolong the life of the nickel-cadmium batteries, but only for a fairly short time. The thing is that with time, the electrolyte evaporates inside due to constantly high temperatures and restoration becomes impossible.

Replace the defective battery by soldering in a new one using rosin flux. The process should be carried out quickly, without overheating the can, after which the battery is immediately put on a test charge/discharge.

You should buy new elements in specialized stores where experienced consultants can always provide qualified assistance in the selection of the required components.

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