How To Recover A Screwdriver Battery With Your Own
How to restore a battery to a Makita screwdriver
If the battery has ceased to hold a charge, and it is difficult to quickly acquire a new one in the near future, the situation can be corrected if you know how to restore a battery to a Makita screwdriver on your own.
The battery housing of the screwdriver contains power elements (batteries, banks). They can be made from different components, which is reflected in their name:
- nickel metal hydride;
Batteries containing nickel and cadmium are widespread and highly recoverable due to their “memory effect”. This effect is a reversible loss of capacity that occurs if the battery charging mode is disrupted. For example, the battery for a Makita screwdriver was not completely discharged, but only up to 40%, but it was set to recharge. The battery remembers the 40% mark and will continue to work only until the discharge of this value is reached. This inconvenience can be corrected in several ways.
How to restore the battery of a 12 volt Makita screwdriver by applying high currents
A pulse current is supplied to the problem battery using the popular Imax B6 charger, or similar. Before starting work, you must:
- check the electrolyte balance in batteries;
- set the “nickel-cadmium” mode on the charger.
If the amount of electrolyte remaining in the banks is not large, the recovery cannot be started, because this will ruin the battery. The missing electrolyte volume is replaced with distilled water, and only then the reconstruction begins.
To fill in the water, a hole is made with a thin drill on the side of the battery, as close as possible to the upper edge. Water is poured with a syringe with a needle until the can is completely filled. The procedure is repeated for all batteries, the filled elements are left for settling for a day.
After that, a bundle (“cassette”) of batteries is connected to Imax B6 for charging with parameters: 12 volts in short-term pulses, resistance value. 40 ohms. When the batteries are charged to 100%, they are left again for a day. A multimeter is used to check the voltage at each element, finding out if it has dropped. If an undercharged battery is found, water is added again, charged and the voltage is checked again.
When each can holds a charge stably, the drilled holes are sealed with silicone glue.
Replacing a few worn-out cans
Of the total number of cans in a cassette, only a few can exhaust their resource. They can be removed from the solder by replacing them with serviceable ones. First, they look for damaged elements: they measure the voltage of each with a multimeter, recording the results. The sum of the voltages of all batteries must be within 14 volts. Then the battery is connected to a screwdriver, they work intensively for some time, and measurements are taken again. If the difference between the first and second digits for an individual can is 0.5-0.7 volts, it must be replaced.
The technology is similar, only in this version you need to use not a multimeter, but a twelve-volt lamp that draws energy. The advantage of this method is that you do not need to make a bunch of measurements, you do not need to drill anything, the problem definition is relatively quick.
Having checked the unsuitability of the battery, we financially estimate the profitability of replacement and restoration. The question is exclusively budgetary, it depends both on the quality of the original source and on the number of damaged cans.
Motorists are constantly faced with electrolyte replenishment, but for portable electrical engineering, such actions are still abnormal. The electrolyte boils mainly with a forced charge, the reason is frequent, and therefore understanding how to restore the nickel-cadmium battery of a screwdriver by topping up is actual knowledge.
We check the cans again, cut the connecting plates, take out the damaged parts. We make a small hole with a thin millimeter punch from the minus, pour the distillate cube into it. An ordinary medical syringe serves as a measure, we also pump out air with it. We glue the hole with epoxy or specialized metal glue. Putting everything back together, leveling the electrical potential with the help of bulbs. We carry out a full charge-discharge cycle five to six times. it’s done.
What rechargeable screwdriver batteries look like
Power sources are unified regardless of the power of the power tool. Their internal design is very similar, based on a daisy chain of power cells. It can be repaired modularly, without using complex mechanical manipulations.
Regardless of the form factor, there are three main types of batteries:
- nickel metal hydride.
The charge goes through the standard power contacts “plus” and “minus”. There is another type of contacts. managers. They protect the banks of the chemical power source from overheating, leakage and further failure. A thermistor and resistance are “hung” on them.
Elimination of the “memory effect”
The transfer of ions only in fresh elements occurs completely. The essence of the “memory effect” is the clogging of cans with reaction products (salts and alkalis), which are no longer involved in the transfer of current and are stable. The effect does not disappear completely, but there is a way to partially remove it, restoring it to an acceptable value.
The recovery technique starts with a full charge with a small current, the next stage is a complete soft discharge under a small load, when the charge is released through the entire thickness of the plate. Old incandescent bulbs work well, sixty watt will suffice.
Before direct use of the recovered battery, the manipulation is carried out at least five times. The method will not give full power, but as a temporary measure. an effective tool, for several months the walls and ceilings are drilled successfully.
How to restore a screwdriver battery with your own hands
The pricing policy of manufacturers of chemical elements is frankly not encouraging. The cost of one replacement battery for a screwdriver can be up to a third of a new tool. Therefore, you need to know what to do in order to fix it with your own hands, especially since most often it does not take much time.
Elementary physics says: the loss of current in a series circuit is the result of damage to any element. To fix the battery of a screwdriver, you need to find the damaged part. At the same time, all the elements cannot burn out: direct current does not change direction, it will reach the first damaged link and then change its own characteristics.
The following will list the methods that are most often used when you need to reanimate the battery at home.
The battery voltage is uniform. The resistances in the circuit are also known plus or minus. Therefore, we can safely switch to the DCV voltage measurement mode. The battery voltage is used differently:
- nickel battery voltage. 1.2V;
- lithium-ion voltage. 3.6V.
To reanimate a screwdriver battery at home, you need to follow these simple steps:
- We charge all the way.
- We check the banks one by one with a multimeter.
- Each can, the voltage of which is below the minimum threshold, we mark.
- We collect the screwdriver, turn it on. The task is to plant the battery before a noticeable drop in thrust, for this you can give an increased load.
- After planting the battery, we repeat the voltage check manipulation along the circuit. If the voltage drops by 0.5. 0.7 V. the battery cannot be restored.
Restoring the battery of the screwdriver
Lithium-ion cells for any equipment fail forever, it is impossible to reanimate the battery of this type of screwdriver, you can only diagnose it. For elements with nickel leads, there are optional options. Sometimes the problem lies in the charger, and not only in the “receiver”, the output current for amperes and volts needs to be checked there too.
You can restore the nickel-cadmium battery of the screwdriver. Metal hydride electrodes are not subject to “repackaging”, and Ni-Cd batteries are the main type of autonomous power supply for construction equipment.
Basic manipulations to prolong the life of Ni-Cd batteries:
- elimination of the memory effect;
- replenishment with fresh electrolyte.
How to restore a screwdriver battery with your own
A real way to restore 100% battery of a screwdriver, according to my method NI-CAD 1.2V
To begin with, there are a lot of videos on the Internet on recovering batteries from screwdrivers, and they are all the same as a mirror, a brief description of the recovery process that these people offer is that we take the battery, push it with a power supply or another battery, then charge and we use it, and it’s strange that someone doesn’t look, but what kind of stress will be on him when he lies down for a week or two. I offer a completely different way to restore
Which does not just charge and use until the battery dies again. And one that you did and use as a new battery until the need arises. This method was filmed in draft about a month ago, but I never dared to put it on the site, I just didn’t want to reshoot it for a more correct explanation. And frankly speaking, I have very little free time lately.
But now the time has passed which has shown that the recovery option that many people on the network are proposing to use are not destined to live for more than a certain period of time. And my version, even after 2-1 month of inactivity, as if nothing had happened quietly works and charges, I still tried to shoot a new video clip, where in the brink I will try to tell everything.
In fact, everything turned out to be very simple, and in this I was helped by the NI-CAD 1.2V battery I disassembled, which showed me that even with all the zeros on the outside of the device, the patient inside is rather alive than dead and feels very good.
An attempt to regenerate the bus relative to the collector plate was made using distilled water, and the process was quite successful, as a result of which I came up with the easiest way to restore them even without disassembling the batteries!
It is enough to drill a hole in the accumulator in the place behind the rollers. and pour 20.40 ml of distilled water there. after a couple of cycles, cover the hole slightly with silicone.
Before repeating, I recommend watching the video, where I tried to tell the process in more detail.
If you are not sure or afraid of ruining a damaged battery, for example, you can do this with one battery.
If your batteries have voltage and are in the operating range, then you may have a problem with the following:
Also, if you notice that the drill began to work somehow sluggishly and at the same time works as long in time after charging, then you rather have a problem in one or more batteries that are at zero!
A very interesting effect on the battery capacity, it was equal to or slightly more than the indicated battery capacity after restoration by this method.
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. We note right away 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.
To do 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:
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 for an easier 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 in the soldering points of the batteries or the 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, there are 2 ways available for repair, so to speak. This is the restoration and replacement of elements that have become unusable.
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 it is possible 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).
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 mainly for Ni-Cd batteries, but they are usually the most common in household screwdrivers.
So how do you 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 element failure. 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 a Makita screwdriver or any other.
- Screwdriver battery: design and types
- Fault definition
- Is it possible to “reanimate” the elements and how?
- Repair and replacement of screwdriver battery cells
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 (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), cell voltage. 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;
- 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;
- charge / discharge cycles.
- 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 screwdriver’s battery pack. Disassembling the unit, for example, for repairing the battery of the Hitachi screwdriver (pictured below), is very simple. unscrew the screws around the perimeter and disconnect the case.
The housing has four contacts:
- 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 screwdriver battery cells
A more effective way to repair batteries for a 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.
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 section of the connecting wires is incorrect, they will heat up, respectively, the thermistor protection will work;
- in any case, do not confuse the plus of the battery with the minus. the connection is consistent, 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: 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 completely discharge.
It should be noted that the procedure for erasing the “memory effect” should be carried out every three months. Conducted by analogy with the above 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.
Replacing old batteries
In this way, you can repair the battery of any screwdriver. The repair procedure itself is not particularly difficult and begins with disassembling the battery. Using a multimeter, faulty elements are determined, in which the voltage will be below normal. Then they are carefully removed and the exact same mini-batteries are purchased instead.
New parts are installed in their places and connected with existing plates. Soldering or spot welding is used for the connection. In this case, you need to ensure that the battery does not overheat. Therefore, the work must be done accurately and quickly using flux or rosin.
Structural elements of the screwdriver
The screwdriver is rightfully considered an indispensable universal tool. The modern screwdriver market is represented by a large number of models equipped with batteries. Despite the variety of brands and modifications, all batteries have the same structure and only slightly differ from each other.
Each of them includes separate elements connected in series with each other. They are all made to standard sizes and have the same voltage level. Certain types of elements differ only in capacity, measured in A / h and indicated in the marking. There are 4 contacts in the tool body that perform various functions. Including, two are power, designed for charging and discharging. In addition, in the upper part there is a control contact included in the circuit together with a special temperature sensor. It protects the battery, disconnects the charging current and limits it to the set value by changing the temperature.
A fourth contact is separately located, connected together with a resistance. It is necessary when using charging stations of increased complexity, capable of equalizing the charges of all battery cells. Such stations are rarely used in everyday life due to their high cost. A conventional 12-volt screwdriver does not require such stations. One of the reasons for the failure of a screwdriver is a malfunction of the battery, that is, its separate element. In such cases, the daisy chain breaks down the entire circuit. Therefore, it is very important to pinpoint the faulty location. As a rule, this happens after the expiration of the established service life. This problem can be solved in two ways: purchasing a new battery or repairing and restoring an old battery.
How to eliminate memory effect
When a battery is very often undercharged and then discharged, it has a so-called memory effect. That is, the battery gradually, as it were, memorizes the minimum boundary of charging and discharging, as a result, its capacity is not fully used and gradually decreases more and more.
This problem is typical mainly for nickel-cadmium batteries and to a lesser extent affects nickel-metal hydride batteries. In any case, the battery capacity needs to be restored. The memory effect does not affect lithium-ion batteries at all. In order to solve the problem of whether the element can be repaired, it is recommended to completely discharge and charge the battery using a 12 volt light bulb. The positive and negative wires are soldered to it, which are connected to the battery contacts. This procedure is repeated five times or more.
How to restore a screwdriver battery
The battery life is relatively short, on average 5 years. After a set period, the battery suddenly stops working. In such a situation, it is not always possible to quickly acquire a new power source, so the home craftsman has to solve the problem of how to restore the screwdriver’s battery, at least for a short time. In some cases, after a successful recovery, the batteries work normally for quite a long time.
- Structural elements of the screwdriver
- What batteries are used in screwdrivers
- General repair recommendations
- How to eliminate memory effect
- How to properly top up distilled water
- Replacing old batteries
- Battery gas release
What batteries are used in screwdrivers
Correct diagnostics requires knowledge of the main types of batteries used in screwdrivers and the design features of each of them. Each battery consists of mini-batteries connected in series in a single chain. Depending on the material of manufacture, they are nickel-cadmium (Ni-Cd), nickel-metal hydride (Ni-MH) and lithium.
The first option, Ni-Cd, is the most widely used. In these batteries, each cell has a voltage of 1.2 volts, for a total of 12 volts with a capacity of 12,000 mAh. They differ from lithium in the possibility of recovery, since they have a well-known memory effect, which is a reversible loss of capacity. Due to the design features of batteries, not all methods are suitable for their recovery. For example, lithium cells cannot be recovered using Imax B6 charging, since lithium gradually decomposes, loses its quality and does not hold 18 volts. The same method is not always suitable for Ni-Cd batteries, since in some cases the electrolyte can completely boil off in them. However, there are many options for recovery.
Different types of batteries also differ in their own operating voltage. This difference is due to the materials used to make a particular battery. This factor also affects the capacity, which ensures long-term operation of the tool without additional charging. Therefore, during the initial opening of the case, first of all, the type of elements placed inside is determined. The fact is that it is not allowed to replace lithium mini-batteries with nickel-cadmium ones, since their operating voltages differ significantly. Accordingly, the methods of repair and restoration will differ.
General repair recommendations
To repair the battery, you will need measuring instruments. a 2 A ammeter, a 2 and 15 V voltmeter, a tester, an ohmmeter and a milliammeter. The body is manipulated with a screwdriver, scissors and pliers. A magnifying glass may be needed to detect defects.
While solving the problem, can the battery be repaired, the faulty element is searched for and its further replacement. For verification, a standard scheme is used, and on the basis of the data obtained, the state of individual parts is analyzed. It should be remembered that not only mini-batteries may be faulty, but also the terminals of the screwdriver itself. Determining the causes begins with measuring the voltage with a tester on each individual battery. All non-working elements are marked and separated from non-working ones. If the battery quickly discharges, do not disassemble it immediately. First, you can try to restore the battery capacity of the screwdriver. For this purpose, the battery is fully charged and deeply discharged over several cycles. In most cases, capacity is almost completely recovered.
Often the screwdriver stops working due to the failure of the terminals. During operation, they gradually unbend, as a result, the contact is broken and the battery is not fully charged. To repair the charger, you must first disassemble it, and then carefully bend each terminal. After that, you need to check the quality of charging using measuring instruments.
If the measures taken did not help, you just need to replace the defective part. If a specific cause of a malfunction is found, it is recommended to use the recovery methods below.
How to properly top up distilled water
Distilled water only evaporates from nickel-cadmium batteries when they overheat during operation. Therefore, to eliminate the problem and restore their functions, water must be refilled. This procedure is performed in the following sequence:
- After disassembling the battery, mini-batteries will be found inside. Their number may be different, depending on the brand of the instrument. The defective element is determined by a multimeter. In a working battery, the voltage is 1-1.3 V. If this indicator is lower, then the cell is defective and needs to be repaired.
- Further, the faulty parts are carefully removed without destroying the connecting plates. You will need them later for reassembly.
- A hole of no more than 1 mm is drilled in the side part. It is not located in the middle, but closer to the bottom or top of the battery. You only need to drill the wall, without going deep inside the element.
- Distilled water must be drawn into the syringe. The needle is inserted into the hole and through it the battery is completely filled with water. After that, she must stand in this position for at least a day.
- After a day, the battery is charged with a special device, and then left in a charged state for another 7 days.
- After a week, the capacity and voltage are checked again, and if it has not dropped, then the hole in the case is sealed or sealed with silicone.
After all the manipulations, the batteries are assembled into one piece and inserted into the battery case. The connecting plates are soldered or spot welded. Then the performance of the entire battery is checked again, after which it is completely discharged using small loads. The charging and discharging process is performed at least 3 times.
Battery gas release
This repair method applies to lithium-ion battery cells. During the period of operation, they overheat, as a result of which electrolyte evaporates from some batteries. This causes gases to build up inside the battery, causing swelling and bending of the plate. After that, you have to restore the screwdriver battery. The solution to this problem is carried out in the following order:
- Dismantling the battery and finding a faulty battery with a multimeter. Usually, there is no voltage at all in such elements.
- The battery is then pulled out and gas is released from it. In the first case, you will need some kind of flat tool curved at the end. It is brought under the positive contact and the swollen plate is gently pressed down. The gas finds its way on its own, making a hole and going out. In this case, you restore your working capacity only for a short time, since the electrolyte will evaporate completely through the hole and the battery will stop working again.
- In the second case, the positive contact is disconnected using pliers, after which it is slightly bent, but not completely cut off. After that, an awl is inserted under the curved plate and gradually pushed inward. That is, the plate is disconnected from the edge of the battery and the gas is released to the outside. After that, it is inserted into its place, and the hole is closed in the most convenient way. It remains only to solder the contact disconnected at the very beginning.
The most common cause of failure is the failure of only one element. They are connected in series, which means that even a drop in capacity on one battery will lead to a complete malfunction of the entire battery. In this case, we need:
- Screwdriver. Typically, the body is connected with Phillips screws. Some models have foolproof protection and there may be vandal-resistant sprockets, triangles or even spanners.
- Multimeter. Any model is enough, even the cheapest DT-830. Since measurements are taken in millivolts, Soviet dial voltmeters will not work.
Next, you need to follow the instructions:
- The battery is disconnected from the screwdriver. It must be fully charged.
- The case is disassembled.
- Now you need to remove all the jars. There are more of them in Ni-Kd, since the nominal voltage of one section is less.
- Voltage is measured at each bank. For nickel-cadmium. 1.2 volts is nominal. For lithium. the normal voltage is in the range of 3.6-3.8 volts.
- After measuring, you need to look at which banks the voltage is reduced. For example, if the voltage is 3.8 on two lithium batteries, and 3.5 on one, it means that it is defective.
- The battery is assembled and installed in the instrument. Now she needs to be set to zero.
- The battery is disassembled and the voltage is measured again. If the voltage on the alleged element is much lower than on the others, then it is being replaced or repaired.
Topping up with distilled water
Recovering a screwdriver battery with topping up should take place with a completely discharged battery. Ni-Kd batteries are covered with paper. If there was evaporation, then there will be noticeable traces on the surface.
After measuring the voltage, you need to completely discharge all the banks using a 12 volt light bulb. After that, the voltage is measured again. Those elements where it dropped to 0.7 are faulty.
To fill in distilled water, you need to make a hole in the side of the can. A groove is made with a very thin drill (0.5-0.7 mm). Care must be taken so that it does not go inside and damage the plates.
A small amount of water is poured with a syringe with a fine needle. After that, the breakdown must be closed with epoxy resin or sealant.
The battery can now be rocked. Each unit must be discharged to zero again by attaching 1.5 volt bulbs to them. When the procedure is over, the battery is collected and it is necessary to carry out 5 charge and discharge cycles.
Replacing cans in the battery
How to repair a battery for a screwdriver? The easiest way to revive the battery is to replace one of the cans.
It is necessary to find a defective element with a low voltage. To do this, you need to use a tester.
Instructions on how to check the battery of a screwdriver with a multimeter:
- A conventional multimeter has two test leads. a red and a black one. There are two contacts from opposite ends of the can (plus and minus).
- The tester selection lever is set to the “constant voltage” mode. If the multimeter has an automatic selection of values, this is enough. If it is not there, you need to put the lever in position “20”.
- Probes are applied to the contact pads and the voltage is measured. The screen shows the real voltage. If there is a “-” sign in front of the numbers, then the probes need to be changed with each other.
- Each bank is checked using this algorithm.
When a broken element was found, it is simply soldered off and replaced. You need to use a powerful soldering iron so as not to overheat the jar.
How to repair a screwdriver battery at home
The cordless screwdriver is a convenient mechanism that allows you to quickly deal with repairs. Instead of a heavy drill on a wire, it is better to take a lightweight screwdriver that copes with the same tasks without being tied to one place.
They have only one problem. batteries fail. There are many reasons for this:
- Long downtime. Modern lithium-ion batteries require periodic charging and discharging. They drastically lose capacity if they are idle for a long time.
- Temperature drops. Li-Ion does not tolerate high temperatures well. Therefore, there are recommendations for storing these batteries in the refrigerator. But they cannot work in such conditions.
- Overdischarge. The protection system can cause the batteries to discharge to zero and a large current must be applied to the input to resurrect them.
General repair recommendations
How to restore a screwdriver battery? You need to have a basic understanding of electrical engineering. The battery circuit is idle. Ordinary serial circuit (plus connects to minus).
When repairing Ni-Kd, the following recommendations should be taken into account:
- They have a memory effect. The classic scheme for commissioning such batteries is 3 full charges and 3 discharges to zero. The new element must go through the same buildup.
- A similar item. So that it does not get knocked out of the circuit and does not break the battery at all, the new element must fully correspond to the previous rating.
The lithium battery of a screwdriver can be repaired at home if you consider the following:
- They cannot be soldered. Intolerance to high temperatures will lead to a non-repairable condition. To do this, you need to use contact welding (it heats the electrode for a short time without harming the battery). If there is no access to the COP, soldering with a very powerful soldering iron from 100 watts is allowed. Movement must be fast and accurate.
- Identical models. Now there are several main manufacturers of lithium batteries, which are used in popular foreign models of screwdrivers, such as Hitachi, Makita and domestic ones: Interskol, Zubr.
VOTO 12 Volt Lithium-ion Battery Cordless Screwdriver. Battery Replacement
Repair and replacement of battery cells
Do-it-yourself screwdriver battery repair can be more extensive. For example, conversion of Ni-Kd to lithium ones. To do this, you need to purchase several Li-Ion batteries and a charging board. The number of batteries must correspond to the original voltage rating.
As practice shows, most screwdrivers can be easily converted from one type of battery to another, without any problems. Due to the increased exposure, resistance to constant use and higher capacity, the old screwdriver will last much longer.
Car battery recovery methods
Many problems in the operation of the battery appear after improper maintenance or neglect on the part of the car owner. Therefore, drivers should follow the recommendations of the battery manufacturer, keep the device clean, and periodically charge it with a stationary device. In addition, the motorist needs to have an idea of the design features and the principle of operation of the power source.
Battery device and principle of operation
Since the invention of the battery, this device has been repeatedly refined and improved. They all had the main goal of increasing battery performance and longevity. Many manufacturers today use special materials that improve the battery’s properties. But for a simple car enthusiast, it is enough to know the general ideas about the device and the principle of operation of the battery.
Externally, a car battery is a closed plastic container in which a set of negative and positive plates made of lead or alloys based on nickel, cadmium, etc. are hidden. Sulfuric acid is poured inside the battery, which forms a galvanic vapor. When current is applied to the battery terminals, electricity is accumulated. Having reached a certain limit of capacity, the battery is capable of itself becoming source of current with a voltage of 12 V. Each time the car is turned on, the battery is discharged. But as soon as the motor starts working, a working generator must replenish the supply of electricity. However, this idyll is not always observed in the car. Therefore, the battery weakens after each engine start, and soon it does not have enough strength to turn the starter. Car battery repair is carried out only after a thorough diagnosis, identifying the cause of the discharge.
Common battery problems
There are several common car battery problems. In some cases, the battery cannot be repaired, and sometimes the current source can be restored.
- One of the most popular causes of battery failure is plate sulfation. The symptoms of this “disease” look like this. The battery capacity is rapidly decreasing, the power of the device is not enough to turn the starter. In addition, overheating of the plates, boiling of the electrolyte and an increase in the voltage at the terminals are observed.
- A common cause of battery malfunctioning is damage to the integrity and crumbling of carbon plates. This problem is easily identified by the dark color of the sulfuric acid. It is not always possible to restore such a battery.
- The next battery malfunction appears when the adjacent lead plates located in the same section are closed. This problem can be easily identified. The electrolyte in this jar boils away, and the section itself gets very hot. To restore the battery, you must open the battery and replace the damaged plates.
- Incorrect use of the battery, as well as errors in its storage, cause the electrolyte to freeze in frosty weather. As a result, not only the lead plates are damaged, but also the battery case. With such breakdowns, the battery cannot be repaired.
Battery resuscitation methods
When the reasons for the malfunctioning of the power source in the machine are found out, it remains only to eliminate them. You should start with the simplest steps.
- First of all, after removing the terminals from the battery, it is necessary to make an external inspection of the device. If the lead electrodes are covered with a layer of powder of white, blue or green shades, it is necessary to clean the car battery contacts with your own hands from these oxides. For this, the loose mass is removed with a rag, and the terminals themselves are cleaned with fine-grained sandpaper. It is poor contact that can cause poor starter rotation.
- The next step is to charge the battery followed by discharging. Some modern pulsed stationary devices are capable of simultaneously charging and discharging the battery, eliminating sulfation from the plates at the initial stage. If the charger is of the old model, then in this case the car battery is put on recharge for at least 10 hours at a current strength 10 times less than the battery capacity. For example, for a battery with a capacity of 75 A / h, the current is set to 7.5 A. After the end of the process, the battery must be completely discharged. For this, a car light is connected to it. As soon as it goes out, the battery is put on charge again. As a result of such successive cycles, it is possible to reanimate the car battery.
- To eliminate a short circuit in the battery, you can use a special desulfatizing additive. It is added to the electrolyte with a density of 1.28 g / cc. see and leave for 2 days for complete dissolution. Then the electrolyte with the additive is poured into the battery, after which the density is measured again. If this indicator remains within 1.28, then it is necessary to charge and discharge the battery several times. If the electrolyte does not boil during charging and the battery does not heat up, then the current can be halved. After 2 hours, it is necessary to measure the density of the electrolyte, and if it remains at the nominal level, charging stops. The battery has been repaired successfully. When the density changes, add water (if more than 1.28) or sulfuric acid (if less than 1.28) into the electrolyte. After adjusting the density, the battery is charged again.
- Such long-term resuscitation may not be suitable for some motorists. Q: how to recover a car battery at an accelerated rate? For this, the battery is fully charged, after which the electrolyte is drained. The battery is rinsed with distilled water and then filled with a solution of 2% Trilon B and 5% ammonia. After 1 hour, the solution is drained, sometimes you have to repeat the cleaning procedure. The battery is flushed again with distilled water, fresh electrolyte is poured in and a full charge is performed.
Many car battery problems are easier to prevent than fix. It is enough to monitor the cleanliness of the terminals and terminals, and also once every 6 months to fully charge the battery using a stationary device, and the battery will thank its owner with good work. And if the starter and the engine rotate and start easily, then the battery life can be extended to 5-7 years.
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