How to find a faulty battery in a screwdriver. How to recover a lithium battery from a DeWalt screwdriver? Battery types

With prolonged use of the screwdriver or its storage, after a certain time, the battery of the screwdriver becomes unusable. Further use of the tool becomes impossible. The consumer has to consider the option of purchasing a new battery or screwdriver. This solution to the problem is the simplest way out of this situation, in comparison with replacing the batteries in an old battery.

The cost of a new battery is about 60% of the cost of a screwdriver. Each battery contains the same cell type, also sold separately. You can try to fix the battery. Its repair is not considered a very difficult process, but in case of an unsuccessful attempt, the user can purchase a new battery. Below in the article, the issues of repairing a screwdriver battery with your own hands will be discussed in detail.

Battery types

Today, there are screwdrivers on sale with the following types of batteries: nickel-cadmium; nickel metal hydride; lithium-ion.

A separate species has its own advantages and disadvantages. Let's conduct a detailed review of each species.

Ni - Cd batteries.

Positive sides:

the ability to use in low temperatures;
storage at low charge allows you to save the parameters of the tool;
quite common type of batteries;
low cost.

Negative sides:

charge memory effect;
spontaneous discharge;
small capacity;
a small number of charge-discharge cycles.

Ni - MH batteries

Positive aspects: low charge memory effect; small spontaneous discharge; high capacity, relative to Ni - Cd; more charge-discharge processes.

Negative sides: at a low charge, it loses some of its parameters when it is in storage; price range; short service life when used at low temperatures.

Li - Ion batteries

Positive sides:

Negative sides:

the price range is almost 3 times higher compared to Ni - Cd;
after three years, the capacity decreases significantly, since lithium tends to decompose. It is not possible to reanimate such a battery;
can not be used in low temperatures.

You can always restore the battery's performance if the battery is not dry. Otherwise, it will have to be disposed of. How to revive a screwdriver battery is discussed below. The battery will need to be disassembled.

Recovery methods: by squeezing (if there is electrolyte, but at the same time there is a high risk of volume loss); by supplying voltage and current to each element significantly higher than the nominal value.

Identification of faulty elements and their replacement

This will require the following tools:

Battery repair procedure:

Charging the cans to a full charge.
Dismantling the case.
Measuring the voltage with a multimeter on the elements, one by one.
Identification of cells with a voltage below the nominal (the nominal voltage of the Ni - Cd cell is 1.2-1.4 volts, the voltage of the lithium cell is 3.6-3.8 volts).
Marking of the identified elements.
Assembly of the case.
Working with a screwdriver under load until the power is reduced.
Dismantling the case.
Measuring the voltage on the marked elements (the voltage will be lower than that of others), for example, for serviceable elements, the voltage will become equal to 1.1 V, and for faulty ones - 0.8 V and lower.

In this way, faulty elements are identified. storage batteries 12-18 V, which are subject to replacement or restoration.

In Li - Ion batteries, faulty elements are determined in two ways:

Replacing the control circuit from another battery that is suitable in terms of the parameters of the battery, if a malfunction is detected, a replacement is made.
With a charger with adjustable voltage and current. The voltage is set equal to 4 V, the current is equal to 200 mA. The battery is connected. If the voltage rises to 3.6 V, the battery cell is good. Then the rest of the elements are checked.

After repacking the screwdriver batteries, you need to equalize their potentials by charging the cans for 8-10 hours. After cooling down, the voltage on the elements is measured. If everything is done correctly, the voltage will be in the range of 1.3-1.4 V. Then the cans are discharged to the end by using a screwdriver (it is necessary to charge-discharge 3 times). This procedure is recommended to be carried out once every 3 months to eliminate the memory effect.

The cost of a new screwdriver is about 70% of the cost of the battery for it. Therefore, it is not surprising when, faced with a battery failure, we ask ourselves the question - what's next? Buy a new battery or screwdriver, or maybe there is an opportunity to repair the screwdriver battery with your own hands and continue working with an already familiar tool?

In this article, which we 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).

Screwdriver battery: design and types

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

If we disassemble 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 (shown 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), cell voltage - 1.2V;
lithium-ion (Li-Ion), with a voltage of 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;
It is 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 that 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;
More charge / discharge cycles.

Price;
Loses some of its characteristics during long-term storage in a discharged state;
It 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 screwdriver's battery pack. Disassembling the unit, for example, for repairing the battery of a Hitachi screwdriver (shown below), is very simple - we unscrew the screws around the perimeter and disconnect the case.

The housing has four contacts:

Two power ones, "+" 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 charging 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.

Fault definition

We figured out the purpose of the battery structure elements, now we will consider how to determine the malfunction, this is part 2 of the screwdriver battery repair. 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. Hence, 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 a screwdriver is also 12 volt. The procedure is as follows:

We put the battery on charge, wait for the signal of a full charge.

We disassemble the case and measure it on each battery bank. For Ni - Cd, we should have 1.2 - 1.4V, for lithium - 3.6 / 3.8V.

Check all "banks" in which the voltage is less than the nominal one. For example, most Ni - Cd cells have a voltage of 1.3V, and one or more - 1.2 / 1.1V.

We collect the battery and work until a noticeable loss of power.

We remove, disassemble and measure the voltage drop across the "banks" of the battery. On the marked elements, the voltage “sagging” will be greater than on others. For example, they are no longer 1.2V, but 1.0V or even lower.

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

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

If your screwdriver operates on a voltage of 12 or 13V, you can search with 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 a screwdriver battery? In general, 2 methods are 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 a 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.

Screwdriver battery refurbishment is available primarily for Ni - Cd batteries, but these are usually the most common in household screwdrivers.

So how to reanimate a 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.

This method is shown below in the video.

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 screwdriver or any other.

Repair and replacement of battery elements of a screwdriver

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

To carry out repairs, we need either a “donor” battery, in which some of the elements are in good order, or new “banks”. It will not be difficult to purchase them, even on the Internet you can easily find a dozen stores that are ready to send these items by mail. The price does not bite too much, for example, a nickel-cadmium cell with a capacity of 2000 mAh costs around 100 rubles.

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 ...

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

Several nuances should be noted:

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 goes to the plus of the next one.

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 the screwdriver and load it "in full". The main thing is to spare the 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 discharge completely.

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 work of your screwdriver, at least until you have to change it to a new one.

Hello everyone! Today I will touch on the topic of construction and summer cottage activities. I will tell you how to repair or restore a screwdriver battery with your own hands. I must say that a screwdriver is a very convenient thing. Charged the battery and run around without wires twisting here and there. Only over time, such a twist turns less and less. This is due to loss battery capacity... We will talk about them.

How a screwdriver works

Everything is quite simple here. The simplest screwdriver consists of a plastic case, a battery (1), a speed controller (2), a plastic button (3), a motor (4), a gearbox (5) and a cartridge (6).

The insides of the screwdriver battery

Inside the battery, the screwdriver is very simple. The battery cans are connected in series with each other with a metal foil using spot welding. In the simplest case, everything ends with sliding contacts.

More sophisticated batteries include charge and discharge controller boards with cans temperature monitoring. Most often, such boards are installed in brand-name screwdrivers with lithium-ion battery sections.

Types of battery cells

Over the past 20 to 30 years, many portable battery technologies have been developed: Ni-Cd, Ni-Mh, Li-ion, Li-Pol, Al-Ion, Li-S, Mg-S, Li-O2, LiFePO4 and even lithium- nanophosphate. Let's consider the most popular ones.

Nickel cadmium batteries

This is the most popular type of battery section for .

Dignity: They are cheap and can work well in freezing temperatures. They are also not afraid of discharge and storage in this position.

disadvantages: Cadmium is toxic and must be disposed of properly. There is self-discharge and memory effect, low specific volumetric capacity.

Nickel metal hydride batteries

Nickel-metal hydride ones are slightly more expensive, but in general they are about the same in terms of level, maybe slightly better than nickel-cadmium ones.

Advantages: non-toxic, less memory effect and self-discharge, more charge / discharge cycles.

Disadvantages: they are more sensitive to negative temperatures, they are afraid of storage in a discharged state - they lose capacity.

Lithium Ion Batteries

Lithium-ion batteries are increasingly used in even budget-class screwdrivers.

Advantages: no memory effect - can be charged and discharged at any time, large capacity with smaller dimensions, low self-discharge, a large number of charges / discharges.

Disadvantages: high price, danger of excessive heating during intensive charging and discharging.

Lithium polymer batteries

So far, lithium-polymer batteries are little used in screwdrivers, but with the development of technology, they will most likely begin to be installed there in large quantities.

Advantages: higher capacity with smaller dimensions than Li-ion, can take any shape, voltage during discharge holds better, low self-discharge.

Disadvantages: high cost, heating during operation and fire hazard.

Recovery of battery cells

Here I will give a story from Master Sergei for the restoration of a nickel-cadmium battery of a screwdriver. The owner began to complain about the short operating time of the electric screwdriver and the fact that "the battery does not hold." Disassembly of the battery case showed that there are factory-made Ni-Cd cans from Liang for 1000 mAh.

Recovering a Ni-Cd battery can be done in a fairly simple way. Several deep discharge and charge cycles need to be done. In such extreme modes, hard-to-reach areas of accumulation of battery charge begin to work, the return from which has deteriorated due to memory effect, violation of operating or storage conditions.

Such problems arise not only with screwdrivers. The battery-powered radio-controlled model industry has long since solved the problem of automated discharge / charge. There are special chargers for this.

Master Sergey had Vista Power AK610AC. This is a charger with the function of charging a power of 90 W and discharging to a load of 20 W. This is a great professional touch-screen device! This can be found on Avito for about 5,000 rubles.

Instead of such a charger, you can use something more Chinese, for example, at a price of about 2000 rubles.

It is best to start a cyclic battery recovery with a deep discharge of the battery and then immediately charging.

After the first cycle, the capacity during discharge was 707 mAh, and when charged, it was 879 mAh. As you can see, the capacity has decreased by 30% compared to the one declared by the manufacturer.

The second discharge / charge cycle showed 781 mAh / 937 mAh numbers. As you can see, this is 10% more than the previous values.

The third battery recharge cycle showed slight deviations from the previous second recharge. So that's enough. If you see on your batteries that the capacity is growing, then you can continue.

Battery types

According to their design features, batteries are distinguished in the form of sliders and clips.

Battery screwdriver in the form of a slider

But these are insignificant differences compared to the types of batteries. Both the slider and the clip are used in different types of batteries.

Cage-shaped screwdriver battery

There are three types of cordless screwdriver batteries:

Nickel - cadmium (Ni-Cd).
Nickel - metal hydride (Ni-Mh).
Lithium - ionic (Li-Ion).

Lithium polymer batteries (Li-Pol) are not available for screwdrivers. Their main areas of application: smartphones, cell phones, tablets, laptops, radio-controlled devices, electric vehicles.

Nickel - cadmium batteries are the cheapest, quickly charge, have more than a thousand charging cycles. The batteries are resistant to use in low temperatures. But they have a memory effect. That is, they can be charged only after a 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 in the highest demand.

Nickel - metal hydride batteries are more expensive, non-toxic, and have a low memory effect. Self-discharge current is higher than nickel - cadmium. The capacity is higher, the charge cycle is more than five hundred. These batteries do not tolerate high discharge rates worse. They are less suited to making the most of the power of the tool. They need to be constantly recharged.

Lithium - ion batteries are more expensive, more powerful, and fast charging. They have no memory effect. Low self-discharge current. The voltage of the battery cells is higher, therefore their number is lower. Consequently, 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 or screwdriver case that monitors battery performance. A multi-level multi-stage protection is formed:

From high fever.
From full discharge. These batteries are afraid of full discharge and cannot recover if the discharge is below the permissible rate.
Short circuit.
Overcharge, as an explosion may occur.
Overload currents.

The control board installed in the battery case is more efficient. When the battery is located separately from the screwdriver and is not used, 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 the problem with the batteries:

flows;
not removable;
decreased capacity;
not charging;
the charging and discharging times are reduced.

Nickel batteries can be recovered. And lithium is not allowed, since lithium decomposes in them. Here you can only replace the unusable batteries.

How to properly repair yourself.

Please be patient and start repairing.

We disassemble the battery.

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

Video: How to disassemble a screwdriver battery

Several sequentially welded elements are located inside. This cassette provides the required voltage and current characteristics for the battery. Some nickel batteries have a thermal sensor attached to the cells.

Nickel battery thermal sensor attached to the elements

Things get more complicated with lithium-ion batteries. There is a control board, and the elements are wrapped in a protective case or film.

Lithium - ion battery

How to increase battery capacity.

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

New nickel-cadmium batteries must be rocked before first use. Fully discharge and recharge three times. The capacity will become maximum. If the instructions for the device say that the buildup should include a larger number of charge cycles, then follow these recommendations. During operation, completely discharge the battery before charging.
Nickel-Metal Hydride batteries have less memory effect, so they can be swung once before using for the first time.
Lithium ion batteries do not need to be rocked. Simply charge them up to full power.

A 12 volt lamp load is used to discharge the battery. 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 discharge the battery

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

Imax b6 charger

Video: Review of the imax b6 charger

Diagnostics.

After fully charged, disassemble the battery. Examine elements for bulging and oxidation. Measure the voltage of all elements with a multimeter or tester. Voltage limits for different batteries:

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

Diagnostics by a tester.

Diagnostics by tester

The battery cans are paper wrapped. The voltage is applied to each element. If all cells have normal voltage, discharge the battery to half the capacity. Measure the voltage again. Those elements for which the voltage has dropped by 0.5 - 0.7 volts compared to the average must be restored or replaced. They say about such banks "flows".

Video: How to check the battery status

Why is it not charging.

If the charger is ok, check the contacts between the battery and the charger. The contacts of the charger could be straightened. This prevents the battery from charging. Disassemble the device and bend the terminals. The second reason may be a faulty or sealed temperature sensor. It needs to be soldered or replaced with a new one.

Charges and discharges quickly.

If the contacts of the battery, charger and tool become oxidized and dirty, the battery will quickly charge and discharge. Wipe the contacts periodically.

Boil-off of electrolyte.

Boil-off of electrolyte occurs due to accelerated charging and overcharging. If the cells are not swollen and after a full charge show the operating voltage, they can be restored without replacement. It is necessary to replenish the empty volume with distilled water.

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

If this method did not help, then replace the cans with new ones.

Video: Adding Distilled Water

Replacement and soldering of batteries.

When you have diagnosed and identified defective jars, you need to purchase a replacement. New elements must be completely the same in size and technical characteristics.

Video: Replacing cells in the battery

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

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

Lithium batteries can be sourced from an old laptop battery or you can buy new ones. Laptop 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 overcharged, they will die safely. It is allowed to connect in parallel exactly the same batteries, then they will work as a whole. Purchase a battery protection module for series-connected batteries 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 numbers of batteries

Holder for 1 battery

Holder for 2 batteries

Holder for 3 batteries

Holder for 4 batteries

Parallel connected elements can be added to increase the capacity. Lithium batteries cannot be soldered. They can be put into holders and the contacts of the holders can be soldered. 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 be damaged.

For resistance welding we need:

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

Put the tape on the battery, press the contacts at the weld. Inject current for a short time. On the battery, this can be done by a sharp short contact with the terminal. A button is placed at the input of the primary winding of the transformer. For the convenience of welding, connect the elements with glue. Cook according to the pattern, bending over small pieces to secure the test leads for the module. Solder the "+" and "-" of the entire assembly to the module.

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

The exit from the battery must be done with thick wires. If you do not have a large diameter heat shrink tubing, wrap it with duct tape. The resulting battery will be very compact and neat.

Heat-shrink tubing.

Heat shrink tubing for batteries

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

Video: Converting the battery to lithium - ion

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

Restoration and repair

Basic techniques for recovering nickel batteries:

Consolidation (compression).

Elimination of the memory effect.

Adding distilled water instead of boiled away electrolyte.

You can squeeze the jar with pliers neatly 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 easy to detect. After a full charge, the battery is quickly discharged during operation. After a few hours, it functions again. To erase the memory effect, an electrical impulse with a capacity greater than usual is applied to the battery.

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

Lithium-ion batteries are non-recyclable. They are being replaced by workers. It is necessary to unsolder the control board, and replace and assemble inoperative elements in the same way as when converting a battery to a lithium-ion one.

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 "nimh" mode and watch the voltage carefully. When it reaches 3 volts, switch to "liion" mode. Continue charging normally. This process needs to be done for a short time. And be sure to control the tension. If you leave the battery on a charge and forget about it, it will recharge and fail. If this does not help, then look for defective batteries and replace them.

Video: Charging the lithium-ion battery from imax b6

How to store it correctly

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

Discharge nickel - cadmium batteries before storage, but not completely, but so that the screwdriver does not work at full strength. After long-term storage, shake the battery in the same way as before using for the first time.

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

Charge Nickel Metal Hydride batteries fully before storing. If not using for more than one month, recharge periodically. After long-term storage, do not charge for 24 hours.

Lithium ion batteries can be charged at any time. They have the lowest self-discharge current. Above all, do not 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 carry out the diagnostics correctly, you can independently repair all types of batteries.

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Quick repair of a screwdriver battery with a do-it-yourself battery replacement

Hey! Today we will repair the screwdriver battery. Did you know that the history of the creation of the screwdriver goes back to the deep Middle Ages - already in the 15th century, when the knights put on armor before the battle, and the squires helped them twist parts of the armor, guess what? With a screwdriver!

This went on for a long time, until in 1907 the Canadian inventor Peter Robertson patented the Robertson screw with a standard square hole into which a screwdriver tip was inserted. Since that time, screws began to be produced on an industrial scale and used in households. Later, in 1934, inventor Henry Phillips redesigned the head of the screw and a Phillips screw was introduced into which the corresponding screwdriver was inserted. By that time, the engine had already been invented and the idea of creating a "screw and screw rotator" was in the air. However, there were big problems with the batteries - their weight and dimensions. The problem was solved only in the 1980s, when the first nickel-cadmium Ni-Cd and lithium-ion Li-Ion rechargeable batteries appeared.

The USA and Japan were the first to master the production of household and professional cordless drills and screwdrivers. All this happened thanks to the emergence of new energy-intensive batteries of electricity. We will urgently change them inside the Interskol DA-10 / 10.8 ER cordless drill-screwdriver that fell into my hands. The malfunction was as follows - when the button was pressed, the engine simply did not spin, but the LED lit up, although it shone weakly.

Let's start repairing the screwdriver battery by removing the battery

from the handle of the screwdriver and unscrewing the three self-tapping screws, which are located under the sticker at the bottom.

After unscrewing the screws, carefully push back the hooks of the latches as in the photo and remove the lower part of the plastic case of the battery.

Inside we see lithium-ion cans of the Chinese company HighStar model ISR18650-1300 Li-Ion - which means that the batteries have never been changed, because it is known that Interskol is purchased by batteries from this company and inserts them into almost all of its battery tools ...

The photo below shows the insides of a screwdriver battery in all its glory with three cans, produced already in 2011. These batteries lasted five years with active use at a construction site, so the result is very decent - they usually die earlier, probably they were not used in cold weather.

To replace the battery banks, you need to disassemble it even more. I advise you to remember the location of the plus, minus and charging contacts so as not to confuse the wires when reassembling.

Pay attention to the voltage control board on the batteries - especially often stabilizers and protective diodes fail on it. It is imperative to ring suspicious radio elements on this board with a multimeter.

We check the voltage at the output of the battery - it turned out 4.4 volts, and it should be 3.7 x 3 = 11.1 volts in the norm and 10.8 volts with the minimum charge of the batteries. In general, the banks are dead - they need to be changed unambiguously.

We continue to disassemble the Interskol screwdriver battery.

This can be done in several ways - you can unsolder the wires that go to the board.

You can also simply remove the contacts from the top battery cover - the photo shows the shape of the curved contacts, so you can easily remove them yourself.

Under the plastic cover, we see how the batteries are connected to each other - they are spot welded - this is used in almost any batteries of another tool - this is a reliable and gentle connection of batteries - while the destructive heating of the lithium batteries themselves is minimal.

Carefully tear off or bite off the metal tape with pliers to disconnect the cans from each other. From the side of the board, they are also connected with a tape and glued to a cardboard gasket so as not to short-circuit anything on the board. Remember to put it back in place when reassembling the battery.

Due to the lack of a spot welding device, new lithium-ion batteries will be soldered with a well-heated powerful soldering iron very quickly. We remember that heating lithium-ion batteries reduces their service life and is generally explosive.

Pay special attention to the condition of the wires inside the battery - they can be broken or frayed - they need to be properly insulated or replaced with fresh ones. Since I was repairing a screwdriver battery on the road in the field, I had to apply a brilliant invention of the engineering mind - blue radio technical electrical tape.

When disassembling the battery of the Interskol DA-10 / 10.8 ER screwdriver, I was pleasantly surprised - a thermal sensor was installed in the budget screwdriver to control the temperature of the batteries. It turns out that when the lithium cans overheat, the protection circuit turns off the power until the temperature returns to normal. True, the owner never managed to drive him into such a regime. We carefully tear off this thermal sensor so as not to break it - then we will place it in the same place on new cans.

Solder batteries

can be done in different ways, for example with thick wires. I decided to solder a torn-off metal strip taken from old cans. First, I tinned the tapes in the places of future contacts on both sides, then I tinned the contacts of the batteries with a well-heated soldering iron with a drop of solder, but so that they did not get too hot - I let them cool down. Then he pressed the tape to the contacts of the cans and soldered the tape, again without severe overheating of the battery cans.

The minus leads are the hardest to solder, but with a good flux, things go very quickly. True, then it is better to wash the flux afterwards to clean the insides of the battery.

Now the most important thing is what batteries were used when repairing the battery of the Interskol DA-10 / 10.8 ER screwdriver, you ask? Well, I will not hide - these were the most Chinese of the cheap cans that the owner of the device honestly bought in the store. Bailong 18650 batteries with a fictitious capacity of 8800 mAh. This is, of course, laughter and God forbid that they have 2200 mAh, and by how long the screwdriver worked after repair on a full charge, I would have reduced this figure by half. But nevertheless - the screwdriver is urgently repaired and pleases the owner.

When assembling, do not forget to replace the cardboard gasket between the banks and the board so that fresh soldering does not close anything on the board.

This completes the repair and restoration of the lithium-ion battery of the Interskol DA-10 / 10.8 ER screwdriver. Almost all batteries of popular screwdriver manufacturers are repaired in approximately the same way: Bosch, Makita, DeWALT, Metabo, Hitachi, Elitech, Skil and my favorite Bison. This concludes my story about repairing a screwdriver battery. Ask questions in the comments, or even better in the appropriate thread on our forum or write to the Solder Master personally by mail.

Best regards, Solder Master. Happy repairs!

masterpaiki.ru

Screwdriver battery repair: how to restore the battery

Any screwdriver is equipped with two battery packs, which allows you to work with it for a long time. But sooner or later one has to deal with the fact that the battery runs out, does not charge at all and needs to be replaced. Buying a new one is often difficult, and if it does, it is at a very high price. Therefore, they say that it is easier to buy a new tool, or to repair the battery of a screwdriver yourself.

There are a large number of videos on the Internet in which electronics lovers clearly show how to repair a screwdriver battery with their own hands. If you are seriously puzzled by the question, think about saving money and whether you can fix the battery of a screwdriver with your own hands, watching such videos can be a good start in order to repair the battery yourself in the future.

How to disassemble the battery

Accumulator blocks of household tools are almost the same in their device, regardless of the tool model (Bosch, Makita, Hitachi). They are packed in a two-piece plastic case. The number of batteries may vary depending on the output voltage of the instrument being used. All elements are soldered in a specific sequence. The lead ends or terminals, at which battery voltage measurements are usually made, are brought out.

Most of the battery packs of a screwdriver or drill are designed in such a way that they are very easy to disassemble, regardless of whether we are repairing the battery of an Interskol screwdriver, or another model. Several fixing screws need to be removed using a regular screwdriver. There are batteries that are difficult to disassemble, but can be disassembled with a screwdriver and a pocket knife. The adhesive layer is removed with a knife, and two mating surfaces are moved apart with a sharp self-tapping screw.

The difference between the batteries of screwdrivers from each other may lie in the presence or absence of a thermal sensor, which automatically turns off the battery under critical heating conditions (above 50 ° C). The sensor constantly monitors the temperature not only under load, but also under the conditions of the current battery charge. The controller reads all the data and processes them, "remembers" the capacity and other indicators. As soon as the capacity reaches 80-90%, and the voltage is 14 V, the control unit turns everything off. Such batteries serve for years without losing their technical characteristics.

There are a large number of inexpensive screwdriver models on the market. Cheaper devices do not have such technical devices, and all processes must be monitored independently.

Types of battery repair

How to reanimate a screwdriver battery? Three ways can be distinguished:

express repair of the battery by the zapzapping method;
replacement of individual cells in the battery;
replacement of all elements of the battery pack.

Express repair of nickel-cadmium batteries using the zapzapping method

Translated from English, this means burning a nickel-cadmium battery, applying short high-current pulses for several seconds. We can say that this is a kind of emergency resuscitation of batteries. It should be noted right away that this option is quite risky, and not every battery is capable of withstanding such "shock therapy" with a high current. It is only possible to use high current if nickel-cadmium batteries are installed in the screwdriver. Other batteries (nickel-metal hydride, lithium-ion) should not be exposed to such an effect.

The essence of the purge is to destroy the crystals formed inside the nickel-cadmium batteries with a high current. These crystals are called dendrites, and as they grow, the capacity of the battery will gradually decrease. "Pumping" with high currents quickly destroys the formed crystals and sharply reduces the self-discharge of the battery.

It is argued that zapzapping can be effective for any NiCd, even if they are completely discharged to zero or have been left without use for 10 or 20 years. The question is always the probability of a successful repair in such "difficult" cases - when the batteries are "repaired" in this way, it will either be successful or not. However, it doesn't hurt to try to revive them. Observing the utmost care, of course.

To carry out zapzapping you will need:

any high-current charger;
a multimeter to monitor the voltage;
welding machine;
crocodile-type clip;
zapping electrode;
protective equipment.

Do not use an ordinary power supply as a charger. Even if the current strength of such chargers is 10-15 A, they will not withstand strong voltage. Using a double-sided clamp, one terminal provides a tight contact, and the other terminal will hold the electrode itself. It is impossible to hold it with your fingers: during burning, it will glow hot. A zapping electrode is a piece of wire that is coiled in a tight bundle (no insulation). Its cross section is a maximum of 1.5 mm2, and its length is 6-7 cm.

Instead of a higher quality welder, especially daring electronics enthusiasts repair batteries using a regular soldering iron. But a spot soldering tool will be preferable when repairing. Protective equipment (gown, goggles, special non-flammable backing) is necessary because sparks always appear during high current blowing.

Work progress

It is better to purge each battery separately, the algorithm of actions is as follows:

Fix the electrode with the minus sign on its minus pole. Do not mix up the polarity, an important point.
"Blow" the positive electrode with short pokes, their frequency is 2-3 times per second. Usually, for a can with an output voltage of 1.2 V, blowing must be done for 3-4 seconds with a frequency of 2-3 small pokes per second;
Measure the voltage readings after the first stage. It should be raised to a maximum of 1.3 V. If the voltage is higher, the time of poking or their number should be reduced.

You need to poke very quickly and carefully, not allowing the electrode to weld even for a short time to the Ni Cd pole of the screwdriver battery, in order to avoid complete burning of the battery. It is recommended to put on a protective intermediate one on the positive electrode, or to hook a "crocodile" to protect the surface of the battery pole.

The procedure is repeated up to 25 times - until the battery capacity is restored. During the entire process, it is necessary to constantly monitor the temperature of the batteries. The intervals between zaps must be at least 15 minutes. Only in this case will the reanimated battery have a chance to extend its service life.

Replacing individual cells in the battery

If the capacity of the battery drops, it means that at least several of its cells are out of order. All batteries cannot "sit down" at once, so first you need to find the lowest-capacity batteries in the chain, and then disassemble the battery and replace them with new ones.

New batteries can be ordered from any online store. At the same time, it is important to buy those elements, the type and capacity of which fully correspond to the previous ones. If there are nickel-cadmium batteries in the screwdriver, then it is worth purchasing the same ones with the same level of capacity. If you manage to get the same battery, you can remove the most capacious elements from it and put it in the one that is being repaired.

How to identify "weak links"

The search for dead batteries in the circuit can be done in two ways:

using a multimeter;

For the first method, you only need a multimeter:

charge the battery completely;
disassemble the battery case;
measure the nominal U on each battery (nominal for nickel-cadmium batteries - 1.2 V, for lithium-ion - 3.6 V);
mark elements with a cross on which U is lower than nominal, so as not to be confused with others;
collect the battery;
turn on the screwdriver;
work them until a noticeable decrease in power;
disassemble the battery again, measure the U values a second time.

On batteries that are marked with a cross, the voltage "dips" will be much greater than in the rest - most often, below 1 V. As for the difference between the U values in the battery, if it is at least 0.5-0.7 V, this is essential.

The second way to find dead batteries is less laborious and simpler. If the output voltage of the screwdriver is 12 V, you will need a lamp with the same output voltage.

Course of action:

charge the battery completely;
connect the lamp as a load to both poles of the battery;
wait until the battery is completely discharged;
measure the voltage indicators at the terminals of all elements with a multimeter.

"Dead" batteries are easy to separate because their voltage drops the most after being discharged.

Repair

So, the elements that were out of order were found, new ones were purchased, and now you can proceed directly to the repair of the battery.

To repair the battery, you will need:

soldering iron;
low corrosive flux;
tin;
copper plates (in case the "relatives" broke during parsing).

It is not necessary to use spot welding in case of partial repair of the battery. But during soldering, you need to be careful not to overheat the elements. It is best to connect the batteries with each other using the plates that they had. If they break during the parsing of the battery into separate elements, then you will need to make new copper plates.

Do not forget about polarity. Each battery cell for a screwdriver is connected to the neighboring one according to the principle of a certain sequence. The minus of one can must be connected with the plus of another, and the minus of the other can must be connected with the plus of the third, and so on.

After the chain is reassembled, care must be taken to ensure that the voltage potential of all elements is equal. To do this, you should leave the batteries on charge for the whole night, then they should cool down over the next day. After that, the voltage is measured at each element. If the soldering and the charging cycle were carried out correctly, then the multimeter will show approximately the same U figure on all batteries - 1.3 V.

Now you need to carry out at least two charge-discharge cycles for the battery in a natural way: place the repaired battery in your own screwdriver and work it until it is completely discharged.

By the way: partial repair of a Li-ion battery in a screwdriver can be carried out in a way that requires minimal financial costs. If 18650 batteries are installed in the unit, it is really possible to borrow the same from an old non-working laptop, if possible.

Replacing all elements of the battery pack

The required number of cells can be ordered from any online store, depending on the number of old batteries. It is important to pay attention to the fact that they are all initially of the same capacity.

You can completely replace all the cells of the battery pack with new nickel-cadmium batteries. They are much cheaper than nickel metal hydride batteries and are the most tenacious and hardy batteries compared to other batteries. Recently, however, the practice of self-alteration of batteries "from cadmium to lithium" is increasingly practiced, in other words, the installation of new lithium-ion batteries instead of old Ni-Cd.

Despite their reliability, nickel-cadmium batteries can quickly fail because they are daisy-chained to each other without a balancing board. If the batteries are of the same production batch, their parameters will still have a large scatter among themselves. With this connection, one cell will charge faster, another slower, and the third can recharge.

If cadmium battery manufacturers made balancing boards like lithium batteries, Ni-Cd could last much longer. But for manufacturers it is simply unprofitable. As for lithium cells, balancing boards are installed in such battery blocks because without them overheating can occur with a subsequent explosion: here the manufacturers simply have nowhere to go. You can find out which battery is better for a screwdriver here →

To completely replace the batteries in a screwdriver from nickel-cadmium to lithium-ion, you will need:

the number of elements equal to the number of the previous ones (with the same capacity indicator);
balancing board 5S (its amperage depends on how many volts the screwdriver is designed for);
tester or multimeter;
a soldering iron with a good "tip";
high quality flux and lead solder;
silicone wires AVG 16;
heat-resistant tape and hot melt glue.

Discharge the batteries before soldering. Remove old batteries from the block and release contacts. It is better not to throw away the old thermal sensor, but leave it as an additional protection against overheating of lithium.

Now the main thing is to properly solder the lithium. Cut the wires to the desired length, insulated, in silicone, very thick, to avoid melting when the lithium is heated. A knife is used to clean the areas of batteries for soldering.

Heat the soldering iron well, up to 300 ° C, and start soldering with flux and lead solder. The flux must be of good quality, indelible, non-conductive. Never use acidic fluxes. Soldering should be no more than 2 seconds to avoid overheating of lithium. In order for the heat to go away faster, after soldering, you can attach any iron object to the battery that takes heat.

Allow the batteries to cool and combine the pros and cons as usual. Check the total voltage. Its indicator should be on average 20.7 V if there are 15 elements.

After measuring the voltage, the board is connected. All its wiring must be laid with special gaskets so that nothing is "short-circuited" during operation. The entire battery pack is bonded with heat-resistant tape specially designed to insulate batteries and their contacts.

The wires and the connector are soldered. If the contacts are loose, they can be put on hot melt glue. Now, finally, you can finally assemble the battery pack of the screwdriver and check its operation.

Sometimes it seems that it is very difficult to repair the battery of a Hitachi screwdriver (or other tool). But if you understand the general principles, such as the basics of electronics, the device of batteries from the inside, types of batteries and the main principles of proper soldering, it becomes clear how to repair a battery for a screwdriver yourself. This will not only save money, but it will also help you acquire valuable and useful skills.

batteryk.com

Do-it-yourself screwdriver battery repair, how to check with a multimeter, restore the battery and replace its elements

In the arsenal of any good owner, there will certainly be a power tool common today in everyday life - a screwdriver. Its main advantage is mobility. After all, this device is powered by removable batteries, which makes its use as convenient as possible, since you do not need to connect to an electrical outlet. But what if the battery of the screwdriver is out of order? Buying a new one will be quite costly, because its cost in some models reaches 50-70% of the price of the screwdriver itself. It will be much more practical to immediately purchase a new tool, which includes as many as two batteries. But you can still extend the service life of an old screwdriver by repairing a failed battery.

What is a screwdriver battery

In any models of electric screwdrivers, such an important element as the battery looks about the same. It is a plastic box with up to a dozen (and sometimes more) batteries inside. They are connected to each other in a serial chain and are arranged in such a way that the terminals of the first and last banks in the chain are closed to the contacts that provide power to the instrument and connect to the charger.

A screwdriver battery is a chain of rechargeable batteries connected in series

The battery of a screwdriver of any type has a fairly simple design, which can easily be understood by anyone who is even a little familiar with the basics of electrical engineering. In addition to batteries, the body of the battery pack may contain:

Depending on the type of batteries used, screwdriver batteries are of the following types:

nickel-cadmium, designated with NiCd symbols and rated for a nominal voltage of 12 V;
Nickel-metal hydride (NiMh) with the same rated voltage as type 1 cells (12 V);
lithium-ion (Li-Ion), the voltage of which, depending on the number of cells used, can range from 14.4 to 36 V.

Different types of batteries provide different rated voltage and power of the screwdriver

Rechargeable batteries of the first type (NiCd) are the most common in modern tools, primarily due to their lowest cost. Particularly often, batteries based on nickel-cadmium alloy can be found in budget models of screwdrivers. They are not afraid of low temperatures and can be stored in a discharged state without losing their characteristics. Of the shortcomings of such batteries, it can be noted:

a pronounced memory effect, when, when the charge is incomplete, the battery seems to remember to what value its capacity was used, and in the future it is no longer charged above these parameters;
small capacity and a small number of charge and discharge cycles;
susceptibility to self-discharge, when an unused charged battery gradually loses its charge;
high toxicity when opening the can due to the cadmium included in the battery.

In order for the new battery for the screwdriver not to lose its capacity, the first few times it must be charged within 10-12 hours, even if an indication appears that it was charged much earlier. In the process of working, it is better to use the battery until it is completely discharged, and then immediately connect it to the charger until it is fully charged.

Nickel-metal hydride elements are also common in modern screwdrivers. They consist of environmentally friendly cells, but are more expensive than nickel-cadmium batteries. They have lower self-discharge and memory effect and more charge cycles than NiCd cells. But they are afraid of low temperatures and in a discharged state they also lose their characteristics.

The most expensive are lithium-ion batteries, which, in comparison with the first two types, have noticeable advantages:

Among the disadvantages of batteries of this type, it should be noted their short service life. After three years, lithium begins to decompose, and the battery loses its capacity beyond recovery.

Typical malfunctions of the screwdriver battery

Despite the fact that screwdrivers are equipped with different types of batteries, they all have the same design and similar malfunctions. The following breakdowns of this device are most common:

loss of capacity by one or more batteries;
mechanical damage to the battery pack circuit (tearing of the plates connecting the cans to each other or to the terminals);
drying out of the electrolyte;
decomposition of lithium in Li-Ion cells.

Loss of battery capacity is the most common defect in screwdriver batteries. Its essence lies in the fact that the loss of the charge capacity of at least one battery does not make it possible to fully charge the rest of the banks. Receiving a low-quality charge, the battery is quickly discharged.

Such a malfunction may be a consequence of the memory effect or drying out of the electrolyte in the cans due to their heating during charging or under load. This defect in batteries of any type can be rectified by yourself, without contacting a service center. In this case, you can try to repair faulty elements or replace them. It will not be possible to restore only lithium-ion battery cells that have lost their capacity as a result of lithium decomposition. Such cans can only be replaced with new ones removed from an inoperative battery pack.

A battery malfunction of a screwdriver can be caused by a loss of capacity of one or more batteries, so it is easy to fix it by replacing them with new ones or known to be working

DIY screwdriver battery repair

Most of the defects in the battery pack of a screwdriver can be eliminated on your own if you know the cause of the malfunction and how to deal with it.

Diagnostics of malfunctions of the screwdriver battery

Before proceeding with the repair of the battery, you need to diagnose it and identify the cause of the malfunction. This requires:

Video: how to completely discharge the screwdriver battery

Having found the faulty batteries, it is necessary to decide on the method of their repair. Two options are possible here. The first is to reanimate defective batteries by flashing them with a current with a higher voltage or add to cans of distilled water if the electrolyte dries out. But these measures are temporary; in the future, the malfunction may appear again. Another method of repair is more effective, which consists in replacing defective batteries with new or used ones, but known to be serviceable.

Video: finding defective batteries in a screwdriver battery

Recovery of rechargeable batteries

Restoration of the lost capacity of the battery is possible only for batteries with a memory effect. These are nickel-cadmium and nickel-metal hydride batteries. To do this, you will need a more powerful charger with adjustable voltage and current parameters. Having established a voltage of about 4 V and a current strength of 200 mA, we apply this current to the batteries in which the maximum voltage drop is detected.

Defective batteries can be repaired by compression or compaction. This procedure is a dilution of the electrolyte, the volume of which in the battery bank has decreased. This requires:

The procedure described in point 5 can, under certain conditions, restore the battery's performance if the memory effect is the cause of its malfunction.

Video: the process of restoring the capacity of the screwdriver batteries

Replacing batteries

The most effective way to repair a screwdriver battery is to replace a defective can. To do this, you can use a new battery, which can be easily found on sale today, or remove a serviceable bank from an inoperative battery pack. Replacement work must be performed in the following sequence:

It is important not to overheat the jar when performing soldering work. Therefore, it is impossible to hold the tip of the soldering iron on the battery for too long.

Repair of battery packs with lithium-ion-type cans is carried out in the same way. The only thing that complicates the repair task is the disconnection of the batteries from the control board. In this case, only one repair method is applicable - the replacement of a defective can.

Video: how to properly solder battery banks of a screwdriver

How to convert a screwdriver battery for lithium-ion batteries

Often, owners of nickel-cadmium-powered screwdrivers want to convert their batteries to lithium-ion batteries. They are attracted by the advantages that can be acquired by such a rework of the battery pack:

to lighten the weight of the screwdriver, for the operation of which fewer batteries are required at the same values of battery capacity and voltage;
get rid of the memory effect, which is not present in lithium-ion batteries;
reduce battery charging time.

In addition, with a certain assembly scheme, you can double the charge capacity, and therefore the operating time of the screwdriver from one charge. The advantages, of course, are obvious, but such a solution also has its drawbacks, which you also need to know in order to weigh the pros and cons. Of the negative aspects of adapting the battery of a screwdriver for lithium ion banks, it should be noted:

higher cost of lithium-ion type batteries;
the need to maintain the cell's charge level strictly within the range from 2.7 to 4.2 V, for which it will be necessary to additionally install a charge-discharge controller board in the battery box;
large sizes of Li-Ion batteries, which will require you to show ingenuity and imagination in order to place them in the screwdriver battery case;
the inability to use the tool with such batteries in low temperatures.

But if the decision to replace the nickel-cadmium batteries is still made, then you need to proceed further in the following sequence:

It may turn out that the assembled structure cannot be charged from an old charger. Then it is necessary to install an additional connector for a new charging.

Video: replacing nickel-cadmium batteries with lithium ion

How to properly store screwdriver batteries

In order for a screwdriver battery to last as long as possible, it must be properly stored, especially when it is not used very often and with long interruptions. In this case, you need to follow some rules.

Cadmium-based battery packs have a memory effect that reduces the capacity of the batteries when the charge is not fully used up. Therefore, batteries with NiCd and NiMh batteries should be stored in a discharged state, and devices with lithium-ion batteries should be charged to half the capacity of the cans. This level can be reached in a time equal to approximately 65–70% of the normal full charge time.

If the battery pack of your screwdriver begins to discharge quickly and does not hold a charge at all, do not rush to throw it away and buy a new one. Its service life can be easily extended using the recommendations above. By doing this, you will save yourself unnecessary costs, because the battery of a screwdriver costs more than half the cost of the entire tool.

Screwdrivers are used in different conditions and the degree of stress they have is 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

According to their design features, batteries are distinguished in the form of sliders and clips.

But these are insignificant differences compared to the types of batteries. Both the slider and the clip are used in different types of batteries.

There are three types of cordless screwdriver batteries:

Nickel - cadmium (Ni-Cd).
Nickel - metal hydride (Ni-Mh).
Lithium - ionic (Li-Ion).

Lithium polymer batteries (Li-Pol) are not available for screwdrivers. Their main areas of application: smartphones, cell phones, tablets, laptops, radio-controlled devices, electric vehicles.

Nickel - cadmium batteries the cheapest, fast charging, have more than a thousand charging cycles. The batteries are resistant to use in low temperatures. But they have a memory effect. That is, they can be charged only after a 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 in the highest demand.

Nickel - metal hydride batteries more expensive, non-toxic, low memory effect. Self-discharge current is higher than nickel - cadmium. The capacity is higher, the charge cycle is more than five hundred. These batteries do not tolerate high discharge rates worse. They are less suited to making the most of 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 higher, therefore their number is lower. Consequently, 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 or screwdriver case that monitors battery performance. A multi-level multi-stage protection is formed:

From high fever.
From full discharge. These batteries are afraid of full discharge and cannot recover if the discharge is below the permissible rate.
Short circuit.
Overcharge, as an explosion may occur.
Overload currents.

Overview of a lithium-ion battery with a chip

Battery problems

What can be the problem with the batteries:

flows;
not removable;
decreased capacity;
not charging;
the charging and discharging times are reduced.

Nickel batteries can be recovered. And lithium is not allowed, since lithium decomposes in them. Here you can only replace the unusable batteries.

How to properly repair yourself.

Please 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 cannot be removed, unscrew the screws on the tool body and remove the top half. One of the buttons was released. Pull the battery towards you, slightly wiggling it in different directions, and it will also come off. When you disassemble the battery, position the buttons so that they easily press into their grooves.
The battery case consists of two parts and can be collapsible and non-collapsible. In the first case, unscrew all screws and separate both parts.
In the second case, the lower part of the body is tightly attached to the upper one and glued. Therefore, to separate them, take a rubber mallet or a piece of wood like a rolling pin and do not tap hard on the seam around the body. If it doesn't work, use a thin, sharp knife. Slide it into the seam and carefully cut through the glue.
Then knock again. Sometimes it happens that the battery is almost disassembled, but in a certain place it stubbornly resists. Do not strike at one point for a long time, as you risk damaging the body. Just take a chisel or screwdriver and pry it in the right place.
When parts of the case are disconnected, buttons may fire, but this does not mean that they are broken. They need to be collected and inserted into place. To remove the top from the batteries, insert a screwdriver into any of the terminals and gently press down on the element. Pull the case up and it will come off.

Video: How to disassemble a screwdriver battery

Things get more complicated with lithium-ion batteries. There is a control board, and the elements are wrapped in a protective case or film.

How to increase battery capacity.

New nickel-cadmium batteries must be rocked before first use. Fully discharge and recharge three times. The capacity will become maximum. If the instructions for the device say that the buildup should include a larger number of charge cycles, then follow these recommendations. During operation, completely discharge the battery before charging.
Nickel-Metal Hydride batteries have less memory effect, so they can be swung once before using for the first time.
Lithium ion batteries do not need to be rocked. Simply charge them up to full power.

Video: How to discharge the battery

Video: Review of the imax b6 charger

Diagnostics.

After fully charged, disassemble the battery. Examine elements for bulging and oxidation. Measure the voltage of all elements with a multimeter or tester. Voltage limits for different batteries:

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

Diagnostics by a tester.

Video: How to check the battery status

Why is it not charging.

Charges and discharges quickly.

If the contacts of the battery, charger and tool become oxidized and dirty, the battery will quickly charge and discharge. Wipe the contacts periodically.

Boil-off of electrolyte.

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

If this method did not help, then replace the cans with new ones.

Video: Adding Distilled Water

Replacement and soldering of batteries.

When you have diagnosed and identified defective jars, you need to purchase a replacement. New elements must be completely the same in size and technical characteristics.

Video: Replacing cells in the battery

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

Battery compartments for different numbers of batteries

For resistance welding we need:

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

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

The exit from the battery must be done with thick wires. If you do not have a large diameter heat shrink tubing, wrap it with duct tape. The resulting battery will be very compact and neat.

Heat-shrink tubing.

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

Video: Converting the battery to lithium - ion

Restoration and repair

Basic techniques for recovering nickel batteries:

Consolidation (compression).

Elimination of the memory effect.

Adding distilled water instead of boiled away electrolyte.

You can squeeze the jar with pliers neatly 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.

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

Video: How to Replace Lithium Ion Battery Cells

Video: Charging the lithium-ion battery from imax b6

How to store it correctly

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

Nickel - cadmium batteries discharge before storage, but not completely, but so that the screwdriver does not work at full strength. After long-term storage, shake the battery in the same way as before using for the first time.

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

Nickel - metal hydride batteries fully charge before storing. If not using for more than one month, recharge periodically. After long-term storage, do not charge for 24 hours.

Lithium Ion Batteries can be charged at any time. They have the lowest self-discharge current. Above all, do not 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 carry out the diagnostics correctly, you can independently repair all types of batteries.