How can you replace the battery for an electric screwdriver • CIMFLOK.COM

DIY screwdriver power supply repair

If the screwdriver’s battery does not charge well and does not want to hold a charge, do not rush to get a new one. Perhaps a relatively simple repair will help fix the situation. We suggest you find out what can be done in a given situation, because for a new battery you will have to pay almost half the cost of a screwdriver.

The malfunction can be eliminated by hand

Recovery

If, as a result of testing, it has been determined that the memory effect is the cause of the incorrect operation of the battery, you can try to restore its working capacity. To do this, it is worth using special chargers that allow you to set the voltage at which charging-discharging will be carried out.

To restore the battery, we set the voltage 2-3 times less than what is indicated on the battery charger. We charge and discharge the cell several times. Such a maneuver often allows you to restore the battery characteristics of the screwdriver.

Charging the cell separately will restore its performance

How to properly store the battery from an electric screwdriver?

It is important not only to use the battery correctly, but also to store it correctly. The most important rule of thumb here is to keep any type of battery disconnected from the instrument. In this state, they will remain efficient for much longer.

But this is not the only condition. There are many subtleties that are characteristic of a particular type of battery:

Nickel-cadmium energy sources should be stored lightly. but not completely!. discharged. Before sending it to the case, work it so that the electric motor of the electric screwdriver depletes a certain amount of energy.

Nickel-Metal Hydride cells are best stored when fully charged. However, minor discharge will not be critical.

Lithium-ion batteries should be discharged by about 50% before being sent to the case for long-term storage.

It is also necessary to properly remove batteries of different types from storage. The most demanding here are nickel-metal hydride batteries. After “de-preservation” they should be put on recharge and left in this state for about 1 day. This is explained by the fact that such batteries are most susceptible to so-called. self-discharge, that is, they are able to lose energy even when they just lie in the case.

The easiest lithium-ion power supplies to service in general and to prepare for work in fairness. Their main feature, as noted above, is the absence of a memory effect. In addition, they have a minimal tendency to self-discharge. This means that even with long-term storage, the level of their charge practically does not decrease. And before starting work, such batteries do not require any special manipulations. At the same time, they are more sensitive to full discharge than their nickel counterparts. If their charge level drops to zero, then this can provoke a shutdown of the built-in protection system. as a result, the battery design may be damaged. Therefore, it will not be superfluous to put the battery that has been in the case for a long time to recharge.

As practice shows, following the recommendations for preparing batteries for operation and storing them helps to significantly extend their service life. This makes it possible to use the entire resource inherent in the battery by the manufacturer. and not spend money on buying a new battery for as long as possible.

Diagnostics

Before starting the repair, you should establish the cause of the malfunction of the screwdriver battery. Most often, incorrect work can be due to:

natural aging;
damage to contacts;
violation of the integrity of the cans due to mechanical stress;
loss of capacity due to violation of operating rules.

To carry out diagnostic work, we disassemble the battery of the screwdriver and carefully inspect the soldering points. We make sure that there are no mechanical damage to all battery cells. You will need a voltmeter or multimeter to monitor the technical characteristics of the product. With its help, the total voltage is monitored. By its value, one can judge about the natural aging and degradation of elements, as well as the failure of the charger.

Diagnostics is an important step

Extending the battery life: storage rules

To use the battery for a screwdriver as long as possible, you must follow certain rules for its storage and use. Especially if the latter happens infrequently and after long breaks.

NiMh and NiCd must be stored in a fully charged state. Memory effect may cause incomplete discharge of charge during subsequent recharging. Lithium-ion batteries should be approximately half charged. To do this, they must be removed from charging after about 65-70% of the time of a full charge.

Battery selection

The main parameter that needs to be taken into account is the supply voltage indicated in the passport or on the case. The motors used in screwdrivers also operate at reduced voltage, losing somewhat in speed and torque. The most affordable of the batteries will be acid for cars, motorcycles, as well as for uninterruptible power supplies.

Motorcycle

They differ in mass in the range of 2-4 kilograms. Voltage 6 and 12 volts.

Automotive

The question often arises whether it is possible to connect an electric screwdriver to a car battery. Indeed, you can use a battery that has worked out its resource, the capacity of which is already small for a car, but sufficient for a hand tool. The standard voltage of car batteries is 12 volts.

Due to the mass of 14 kilograms, it is advisable to use such source at a stationary workplace, scaffolding or mobile platforms. The length of the wire is 2-3 meters. Charging will have to be done by a third-party device due to the high charging current.

Gel (batteries for UPS)

Their advantage is in a sealed body and a pasty electrolyte, which allow the instrument to be used in any spatial position. It is possible to use a charger from an electric screwdriver. Here you can not be afraid of acid burns or spoiled clothes. You can attach the battery directly to a screwdriver or carry it in a bag or s.

How to power an electric screwdriver from a third-party battery

The service life of an electric screwdriver is 5-7 years, and its battery life is at best 2 years. This means that by replacing the power source, it will be possible to extend the life of the beloved instrument by at least 2 years. Of course, it is best to find an original battery, but the problem is its availability and cost.

How to replace the battery for an electric screwdriver

It should be noted right away that handicraft modifications will reduce the mobility of the screwdriver due to the additional wire from the new power source and its weight. On the other hand, the operating time on a single charge will increase to 12–20 hours, versus 2–3 with a native battery. This will be very useful in remote sites without power supply.

For convenience and safety, double-insulated flexible wire such as PVA and ShVVP should be used. Section 0.75 mm 2 and more. You can connect it in two places:

to the handle of the electric screwdriver;
to the body of the old battery.

The cast body is cracked with a sharp blow to the screwdriver, or is separated by a hacksaw blade at the soldering point. Then the old lead battery is removed, and power is connected to the free wires, observing the polarity, from a new source.

Precautions

It should be borne in mind that connecting a new power supply is an interference with the factory design. This means that it is important to pay attention to personal and fire safety. Remember that you need:

observe polarity;
securely insulate wire connections;
use chargers rated for the capacity of this battery.

A minimal knowledge of electrical engineering is sufficient to replace the battery. Locksmith skills will also come in handy. It is necessary to provide increased mechanical strength of the wire connection points.

Nickel Cadmium (NiCd)

This type of battery appeared in the middle of the twentieth century. Nickel hydroxide supplemented with graphite powder acts as a cathode in it. To create the movement of ions from the cathode, an electrolyte is used. potassium hydroxide. The last key element is the anode, which here is made of cadmium oxide hydrate. The second version is metallic cadmium used in powder form.

Nickel Metal Hydride (NiMh)

This type is most often used in AA batteries. They began to be developed in the late 1970s. The main substances for the accumulation of charge and its return are nickel-lanthanum, which serves as the anode, and nickel oxide, which is the counterpart, the cathode. Ion transfer is provided by potassium hydroxide.

Battery selection based on application

So, having thoroughly examined all the key factors, we will discuss with which battery to choose an electric screwdriver for home and professional activities. This will help you not to overpay and have a reliable tool at hand.

Self-discharge

It happens that the tool has not been used for some time and it is unexpectedly needed. At such a moment, it may turn out that the battery is self-discharged, and in order to perform the operation, you must first put it in the charger and wait a few hours. It is inconvenient for occasional use.

Unfortunately, nickel-cadmium batteries, as well as nickel-metal hydride batteries, have such a “disease”. For the first, the self-discharge rate reaches 10% per month, and for the second 7-10%. Lithium-ion is much better in this regard. left to lie without use, they will lose only 3-5% after four weeks.

Response to tool operation at full power

When you need to drill a hole in a dense material or screw a thick and long self-tapping screw, you have to use the tool at full power. In this case, active consumption of charge begins, and the ability to complete the process qualitatively without a drawdown of revolutions depends on the battery’s reaction to this phenomenon.

In view of this, modern Li-Ion batteries are significantly inferior to earlier counterparts. The most powerful in this regard are NiCd and NiMh. When maximum energy output is required, then they are chosen.

What does the battery capacity say?

Battery capacity is written in numbers from 1.0 to 7.0 and is measured in amperes times hours (Ah). The value is deciphered as follows: the specified number of amperes can be delivered by the drive within an hour. But since no electric screwdriver consumes 1-5 A per hour, its use time stretches from 2 to 8 hours. The higher the capacity, the longer the tool can stay in use.

Since the battery is presented in the form of a certain number of cells connected to each other, current flows through it completely. To find a non-working battery cell, you must initially fully charge the entire battery until it is clear that charging is over.

Further, it is recommended to measure the voltage on each individual bank. The voltmeter should not show values below 1.2 Volts. If there are such indications, it means that the battery is not receiving proper power or is not charging.

Important! In order to make sure of your measurements, you need to put a mark on the questionable element and make the assembly back.

So, after several periods of operation of the instrument, it is necessary to reconnect the banks and measure the voltage. Practice shows that the previously indicated bank will have even less voltage than before, since it begins to lose its performance and “slow down” the electric screwdriver.

Methods for replacing batteries in an electric screwdriver

All battery-type devices, including the electric screwdriver, have a significant drawback # 8211. limited battery life.

Diagram of the device of a cordless electric screwdriver.

That is why every owner of such a tool at any time may face such a question as replacing batteries in an electric screwdriver. But before starting the action, it is worth understanding the variety of batteries and their features.

Cordless Screwdriver battery replacement/upgrade

Some features

Charger circuit for an electric screwdriver.

If the electric screwdriver operates on a voltage of 12 volts, then an easier method can be used here. It is necessary to disassemble the battery into its component parts. However, they must remain connected to each other. Since the circuit is in series, it is possible to connect a light bulb as a load to opposite ends of the battery. There should be a voltage of 12 volts here. Fortunately, the purchase of such lamps should not cause a problem. Automotive lamps can be used as there is exactly the same nominal voltage. After that, it is necessary to measure the voltage drops on each specific element. The one at which this indicator turns out to be the highest, and failed.

Troubleshooting

Diagram of the internal structure of an electric screwdriver.

Of course, before proceeding with the repair, it is necessary to make a high-quality diagnosis of the device. It is not always possible to immediately find a specific malfunction. Almost all batteries of modern electric screwdriver accumulators consist of several cells connected in series. They have a specific voltage rating. Everything here directly depends on what type of battery we are talking about.

Cordless screwdriver battery replacement and test (before and after)

So, you need to disassemble the battery. Now each element can be measured with a multimeter. It is necessary to set the nominal battery voltage on it, and then make measurements. This is done quite simply. Each element should have approximately the same readings. Before disassembling the battery, it must be fully charged.

Next, the battery of the electric screwdriver should be assembled and worked with it until the power is completely lost. After that, the mechanism is again disassembled and voltage measurements are made on each bank. If any value is half the nominal value, then this bank is out of order. By the way, there may be several of them, so all defective elements must be replaced. Do not postpone this procedure indefinitely.

Battery types for power tools

There are a huge number of battery technologies, but the most common and popular among them are the following:

Lead acid batteries are most popular in the automotive industry due to their ease of manufacture and low cost. But then, for use in power tools, they did not show themselves much, since they have low power with large dimensions and high weight.
Nickel-cadmium batteries have significantly outperformed lead-acid cells. After all, they are lightweight and compact in size, delivering great power. But, of course, there are negative aspects, in particular, the toxicity of the battery. Since the production of this kind of battery cells is harmful to the environment. For example, in the countries of the European Union, this type of battery is considered prohibited.
Nickel-metal hydride cells are considered to be an improvement over the previous battery type. After all, they are completely safe for the world around them. But there is also a drawback in the form of high self-discharge rates for current.
Lithium-ion batteries, although they have almost ideal parameters, since they have a high capacity, small size and low weight, are not very popular. This is because such a progressive element has a high cost, and therefore is not affordable for every man in the street.

Fault definition

We figured out the purpose of the elements of the battery structure, now we will consider how to determine the malfunction, this is part 2 of repairing the battery of an electric screwdriver. Immediately, we note that all the elements cannot fail at once, and since our circuit is sequential, when one element fails, the whole circuit does not work. So, our task is to determine where we have the weakest link in the chain.

For this, we will need a multimeter, and for the second method of troubleshooting a 12V lamp, if your battery for an electric screwdriver is also 12 volt. The procedure is as follows:

Note. The difference between the cells in the battery of 0.5. 0.7V is considered significant, this means that the cell becomes unusable.

Thus, we have found candidates for “resuscitation” or “amputation” and replacement with new elements.

If your electric screwdriver operates on 12 or 13 volts, you can search using a simpler method. We disassemble the fully charged battery and connect a 12 volt lamp to the contacts “” and “-“. The lamp will be a load and will drain the battery. Next, we take measurements on the battery cells, where the voltage drop is strongest, there is also a weak link.

There are other ways, instead of a lamp, you can choose a resistance, but for this you already need the basics of electrical engineering, and it is doubtful that a resistor with the necessary resistance would be at hand.

Other faults are very rare. For example, loss of contact at the soldering points of the batteries or power contacts of the unit, failure of the thermistor. This problem is more inherent in fakes. Due to the rarity, we will not focus on the battery elements.

With the “problem” elements sorted out, it is necessary to repair. How to repair the battery of an electric screwdriver? In general, there are 2 ways available for repair, so to speak. This is the restoration and replacement of elements that have become unusable.

Is it possible to “reanimate” the elements and how?

Let’s proceed to part 3 of repairing an electric screwdriver battery and immediately make a reservation that the concept of “resuscitation” for lithium. ion batteries is not applicable. There is no memory effect in them, most likely, lithium decomposition has occurred, and nothing can be done about it. In such batteries, it is necessary to find out what the cause of the malfunction is: the element itself or the control circuit. There are two options here:

we change the control scheme from another, but similar to ours, battery, if it helps, we find a replacement and change it;
apply 4V to a cell with a current of about 200mA, this requires an adjustable charger. If the voltage on the element rises to 3.6V. the element is working properly, the problem is in other elements, or in the control circuit.

Electric screwdriver battery refurbishment is mainly available for Ni-Cd batteries, but they are usually the most common in household screwdrivers.

So how to reanimate an electric screwdriver battery? There are two types of “resuscitation” for these types of batteries:

The method of compaction or compression (it will work in cases where the electrolyte is still present, but the volume is lost);
“Firmware” voltage and current greater than the nominal. This method allows you to eliminate the memory effect, and although not completely, but restore the lost capacity.

Note. As a rule, in a nickel. cadmium battery, the main reason for the loss of capacity is the boiling off of the electrolyte, and if it is critically small, no “firmware” will help.

This method, if its result is positive, will not solve the problem of failure of elements. Rather, it will only postpone the replacement of those that have become unusable and in the future you will still need to repair the battery of the Makita electric screwdriver or any other.

Instruments

In this article, which we will conditionally divide into three parts, we will consider: the types of batteries that are used in screwdrivers (part 1), their possible causes of failure (part 2) and available repair methods (part 3).

Electric screwdriver battery: design and types

It should be noted that regardless of the brand of the electric screwdriver and the country of the manufacturer, the batteries have an identical structure. The assembled battery pack looks like this.

If we analyze it, we will see that it is assembled from small elements that are assembled sequentially. And from the school physics course, we know that elements that have a serial connection harmonize their potentials.

Note. The sum of each battery gives us the total voltage at the contacts of the battery.

Typesetting parts or “cans”, as a rule, have a standard size and voltage, they differ only in capacity. Battery capacity is measured in Ah and is indicated on the cell (pictured below).

For the arrangement of screwdriver batteries, the following types of elements are used:

nickel. cadmium (Ni. Cd) batteries, with a nominal voltage on the “banks” of 1.2V;
nickel-metal hydride (Ni-MH), voltage across elements. 1.2V;
lithium-ion (Li-Ion), with voltage. 3.6V.

Let’s consider in more detail the advantages and disadvantages of each type.

The most common type due to its low cost;
Low temperatures, such as Li-Ion batteries, are not scary;
Stored in a discharged state, while retaining its characteristics.
Produced only in third world countries, due to toxicity during production;
Memory effect;
Self-discharge;
Small capacity;
A small number of charge / discharge cycles, which means they do not “live” for a long time with intensive use.
Environmentally friendly production, there is an opportunity to purchase a high-quality branded battery;
Low memory effect;
Low self-discharge;
High capacity compared to Ni. Cd;
charge / discharge cycles.
Price;
Loses some of its characteristics during long-term storage in a discharged state;
Does not “live” for a long time at low temperatures.
No memory effect;
Self-discharge is almost absent;
High battery capacity;
The number of charge / discharge cycles is several times greater than that of previous types of batteries;
To set the required voltage, fewer “cans” are required, which significantly reduces the weight and dimensions of the battery.
High price, almost 3 times in comparison with nickel. cadmium;
After three years, there is a significant loss of capacity, because Li decomposes.

We got acquainted with the elements, let’s move on to the rest of the elements of the battery pack of the electric screwdriver. Disassembling the unit, for example, for repairing the battery of a Hitachi electric screwdriver (pictured below), is very simple. we unscrew the screws around the perimeter and disconnect the case.

Two power, “” and “-“. for charge / discharge;
Upper control, it is switched on through a thermal sensor (thermistor). A thermistor is necessary to protect batteries, it cuts off or limits the charge current when a certain temperature of the cells is exceeded (usually in the range of 50. 600C). Heating occurs due to high currents during forced charging, the so-called “fast” charging;
The so-called “service” contact, which is connected through a 9K ohm resistance. It is used for complex charging stations that equalize the charge on all battery cells. In everyday life, such stations are useless, due to their high cost.

That’s actually the whole design of the battery. Below is a video on how to disassemble a block.

Repair and replacement of battery elements for an electric screwdriver

A more effective way to repair batteries for an electric screwdriver is to replace elements that we have identified as faulty.

Note. When purchasing a new element, make sure that its capacity and dimensions coincide with the native elements.

We also need a soldering iron, a low-corrosion flux (preferably an alcohol flux for rosin) and tin. We are not talking about spot welding, since there is hardly a need to purchase or assemble it for a one-time battery repair

In the replacement itself, there is nothing complicated, especially if at least some. then there is experience in soldering. The photographs show everything in sufficient detail, we cut off the faulty element, instead of it we solder a new one.

when soldering with a soldering iron, try to solder quickly, so that the battery does not heat up, because risk spoiling it;
if possible, implement the connection using native plates, or use the same copper plates, this is important because the charging currents are large and if the cross-section of the connecting wires is incorrect, they will heat up, respectively, the thermistor protection will be triggered;
in any case, do not confuse the plus of the battery with the minus. the connection is sequential, which means that the minus of the previous can goes to the plus of the new can, and the minus of the new one. plus the next.

After the new elements have been soldered, it is necessary to equalize the potentials on the “banks”, since they are different. We carry out a charge / discharge cycle: we set it to charge overnight, give it a day to cool down and measure the voltage on the elements. If we did everything correctly, the picture will be something like this: on all elements the same indicator of the multimeter, within 1.3V.

Next, we proceed to discharge the battery, insert the battery into an electric screwdriver and load it “to the full.” The main thing is to spare the electric screwdriver itself, otherwise you will have to repair it too. We bring it to full discharge. We repeat this procedure two more times, i.e. charge and fully discharge.

It should be noted that the procedure for erasing the “memory effect” should be carried out every three months. It is carried out by analogy with the above-described training.

Such a not very tricky procedure will prolong the operation of your electric screwdriver, at least until you have to replace it with a new one.

Battery selection

How to replace the battery for an electric screwdriver

Makita 6722

For convenience and safety, double-insulated flexible wire such as PVA and ShVVP should be used. Section 0.75 mm 2 and more. You can connect it in two places:

to the handle of the electric screwdriver;
to the body of the old battery.

Removing the old battery

We take out the tool we need and once again make sure that all consumers are turned off. You should also know that when the system is de-energized, unpleasant things will not happen, because there are times when, after replacing the battery, the settings of the central computer are reset and the engine speed begins to float, the radio tape recorder or completely the car electronics can be blocked. To unlock the car or radio, you need a secret code, which is usually entered through the head unit. If you are not sure that nothing like this will happen, then it is better to connect an additional source in parallel. Can use 12V battery from home PC UPS.

And so, remove the protective caps. It happens that both terminals are closed, but more often only a plus. First of all, I unscrew the minus. Why minus you ask. Yes, because the minus is attached to the body iron, and the body is the mass. By unscrewing the minus, you can touch any bolt, metal fastener and so on with the key and nothing will happen. And if you first unscrew the plus and touch any metal part, a short circuit will occur. This is absolutely impossible to allow. We unscrewed the wires, bent them so that nothing would interfere and the next thing we do is fastening. Fasteners are more often found of two types, this is a bar on top of the battery on two pins and the second option is fastening to the body with a bar for the lower protrusion of the battery. They unscrewed, pulled out, put on the ground. Next, you need to prepare the place, get out the rubber mat, shake out the dust, dirt, wash it if possible. If there are traces of oxidation, treat with a soda solution, wipe dry.

Now we clean the terminals with sandpaper from the inside and where there are contacts, if necessary (we look at the state). It is better to do all these actions right away when replacing the battery, rather than you will do it in winter in the cold. Gigantic currents pass through these contacts, the contacts can burn and deform from heating, all this can lead to difficulty in starting the engine and self-discharge.

Very important! Replace the battery only when the engine is off and the ignition is off. Failure to comply with this rule can lead to disastrous consequences.

Motorcycle

They differ in mass in the range of 2-4 kilograms. Voltage 6 and 12 volts.

Precautions

observe polarity;
securely insulate wire connections;
use chargers rated for the capacity of this battery.

Hello dear friends! The cordless electric screwdriver is an indispensable tool in the home craftsman’s arsenal. But, sometimes the battery of your favorite electric screwdriver fails and you think about how to replace it. The cost of a cordless electric screwdriver is 70% of the cost of the battery. Therefore, a difficult question arises: What to do? Buy a new battery or a new electric screwdriver, or it may be possible to repair the old battery with your own hands, or replace it with a cheaper analogue. With my favorite electric screwdriver after six months of operation, the same trouble happened, the battery became unusable, and without hesitation I decided to install a more powerful battery from an old uninterruptible power supply on it.

I soldered the wires to the internal power block of the electric screwdriver, the battery was tightly tied with electrical tape in the place of the regular one. It turned out well, if you do not pay attention to the discrepancy in the supply voltage and the significant increase in weight. The supply voltage of the Interskol electric screwdriver is 14.5 volts, and the battery from the uninterruptible power supply provides 12 volts. As practice and tests performed by me have shown, the discrepancy of the supply voltage does not particularly affect the screwing speed of self-tapping screws.

the electric screwdriver confidently copes with heavy loads when screwing in 100 mm wood screws, and thanks to the increased battery capacity up to 7 A / h, the operating time has increased significantly. A battery charge at an average load is enough to screw about 300 self-tapping screws 50 millimeters long into a tree. The weight of the battery is a little annoying and is 2.3 kilograms.

To charge the battery, I use a homemade charger from a computer power supply. The initial charge current is 10% of the battery capacity, i.e. 0.7 A, charging time is approximately three hours.

Good luck to everyone! See you in new articles!

The average battery life is 4-6 years, with proper maintenance it can last 7-10 years depending on the quality of the product itself. If you live in Siberia, then you must definitely monitor its condition, if you do not service it, then at least change it in time so that at the wrong moment the car does not let you down, this is especially important for a car with an automatic transmission. Let’s say your battery is pretty tired, winter is coming, which means it’s time to replace your old battery with a new one.

How can you replace the battery

The service life of an electric screwdriver is 5-7 years, and its battery life is at best 2 years. This means that by replacing the power source, it will be possible to extend the life of the beloved instrument by at least 2 years. Of course, it is best to find an original battery, but the problem is its availability and cost.

Automotive

Sources:

http://pro-instrument.com/ruchnoj/kak-zapitat-shurupovyort-ot-storonnego-akkumulyatora.html
http://srbu.ru/instrumenty-i-oborudovanie/1627-kakie-akkumulyatory-luchshe-dlya-shurupoverta.html
http://kak-svoimi-rukami.com/2014/03/akkumulyator-dlya-shurupoverta-podklyuchaem-obychnyj/
http://restart24.ru/instrumenty/chem-zamenit-akkumuljatory-v-shurupoverte.html
http://strport.ru/instrumenty/remont-akkumulyatora-shurupoverta-svoimi-rukami
http://pro-avtosalon.info/info/chem-mozhno-zamenit-akkumuljator/