How to revive the battery of an electric screwdriver. Independent remake of the battery for lithium-ion banks
How to repair a battery for an electric screwdriver: determination of a malfunction and restoration
How to repair a battery for an electric screwdriver is a frequently asked question among home masters, because this device has almost every owner in the arsenal. The main advantages of the tool functioning from the battery consider compactness, the ability to work with it even at altitude (due to the lack of power supply). Nevertheless, the battery of this device may fail, and purchase a new one. Is unprofitable, because its price sometimes reaches 60% of the cost of the tool. Therefore, it is recommended to try to restore the battery. How exactly, we will tell you today.
Despite the variety of models of these tools, the battery has a similar appearance in all screwdrivers. It is a plastic box, where there are many components of nutrition. They are fixed with each other in a single chain so that the wiring of the “banks” on both sides is closed to contacts, which provide power to the screwdriver.
All batteries have a primitive structure, which even an inexperienced master can figure out a little familiar with electrical engineering. In addition to power parts in the box of the unit, it is often located:
- Thermoresistor. Allows you to control the temperature of the cans during charging;
- Thermal switch. Automatically blows out parts of the circuit in case of battery overheating;
- Control and control payment (only for lithium-ion batteries).
Elimination of memory effect
Not always restoration of the battery of a screwdriver requires any radical actions. Often to restore the battery capacity, alternating complete charging (to the extinguished charging light) and the full discharge of the battery helps. This method is also called “swing the battery”.
How to erase the battery memory effect
It is associated with the so.Called “memory effect” and is characteristic of the batteries of the screwdriver based on nickel. And it is especially strongly manifested in nickel-cadmium. It occurs when the battery discharged to zero does not fully charge and begins to operate or vice versa. This leads to enlargement of the crystals of the active substance, which reduces the area of its active surface.
Follow the recommendations of the manufacturer for the charge and discharge modes.
The so.Called “training” of the battery helps to remove this effect or significantly reduce it. It consists in repeating the cycles of full charge and discharge.
For this, the restored battery is completely discharged, using, for example, a light bulb. Then they are completely charged and discharged again. Repeat the process of 5 times and if the individual elements of the battery are working, the characteristics will return to the norm or close to it.
Determination of breakdowns
In case of damage to part of the elements that make up the bank, there is a loss of voltage and capacity. The owner of the equipment needs to purchase a new part or repair the standard device. Before the restoration starts, the product is diagnosed, which allows you to determine the malfunctions.
The voltage of the sections of a obviously serviceable battery bank is the same, the parameter depends on the type of elements. For example, for a single section of the nickel-cadmium type, the standard voltage is 1.2 V, for the lithium-ion battery-3.6 V for. Before starting testing by a multimeter, the banks are charged with a regular device (in compliance with the recommendations of the manufacturer of the tool).
To further check the power source with a voltage of 18 volts for the Makita electrical screwdriver, you need:
- Disassemble the bank and measure in each section (in total, 15 standard elements are provided in the design). A serial number or value of the measured parameter is applied to the cases of parts.
- Set the lid in the regular place. The bank is attached to the instrument handle (on contact platforms).
- Discard the battery using an electric tool engine until the performance is reduced.
- Dismantle and disassemble the jar, and then carry out a repeated voltage measurement. Sections on which it decreased to 0.7 V are subject to replacement or restoration (in the case of a nickel-cadmium base).
Checking the load
Load testing involves the use of a 12-volt car lamp equipped with a cartridge and connecting cables. Check allows you to determine damaged jumpers. In the design of the banks, spring terminals were used, which during operation lose their elasticity and do not provide full charging.
To restore the nodes, it is necessary to disassemble the body of the part, and then remove the contacts. Elements are bent and installed in a regular place, if the repair has failed, then the terminal is required.
The load fork for testing the tool accumulators is used in the conditions of service centers. The product allows you to imitate the operation of the electric motor under load. The intensity of the voltage drop determines the condition of the battery.
Determining the malfunction and restoration of the battery of an electric screwdriver
Before proceeding with the battery repair, it should be determined by its malfunction, otherwise the repair will be quite difficult or completely impossible. It should be noted that the failure of all the elements of the battery is impossible, with the exception of rare cases when a long.Term closing of the battery terminals could occur.
To determine the malfunction follows:
- Put the battery on charging and wait until it is fully charged.
- After that, disassemble the case, and measure the voltage of each charger. The difference in voltage in banks for nickel-cadmium batteries can be in the range of 1.2-1.4 V, and the difference in lithium can be about 3.8 V.
- Banks with voltage are less than the nominal, you should mark. After that, the battery must be assembled again and give it the full load until tangible discharge.
- Then disassemble the battery again and by the new measurement of the voltage of each can.
- Typically, the largest voltage subsidence will be in marked elements that will need to be “reanimated” or simply replaced.
Repair/Revive/Recondition cordless tool batteries
If a voltage of 12 V is necessary for the operation of an electric screwdriver, you can try to find faulty elements in a simpler way. For this you need:
- Carry out the battery, then disassemble it and measure the tension of each element.
- Then, with the help of a 12 volt bulb, completely discharge it and measure the voltage of all elements again to determine which of them are faulty.
Instead of a light bulb, you can use the appropriate resistor.
Repair and replacement of the elements of the battery of an electric screwdriver
The most effective method is how to restore the battery of an electric screwdriver is a simple replacement of failed charging elements that were discovered during their verification.
To repair, you need a donor, that is, a second battery, which also has failed banks, if this is not, you can purchase new elements via the Internet. Today there are enough online stores who are ready to deliver new batteries directly to the house with a courier service.
Important. Acquired elements should clearly coincide with the replaced tanks and dimensions.
For repair, you will need to prepare: a soldering iron, tin solder and alcohol flux (preferably).
The process of replacing charging elements itself does not provide any complexity, if only there was a solder skill.
Restoring the battery of an electric screwdriver
Attention. In order not to harm the battery when working with a soldering iron, the soldering must be done quickly.
To connect the elements, it is recommended to use native plates, and if it is impossible to use them, completely replace them with the same size, but from copper. This is necessary for the correct charging process. With a different section of the connecting plates between the elements, they will heat up, and naturally, the termistor will constantly work to protect the charging cans.
You need to carefully take the assembly of the batteries. The connection must be consistent. The minus of each battery is connected to the plus of the next element.
After the full assembly of all elements, their potentials are aligned, since they will be different at this time. To do this, you need to carry out a certain charging cycle/discharge. The renovated battery is completely charged, after which it should stand for about a day. After a day, it is necessary to measure the voltage separately of all elements, and if the assembly was made correctly, the voltage indicator of each element must correspond to 1.2 V.
After that, the battery should be completely discharge again. To do this, the assembled battery, using an electric screwdriver, is given a complete maximum load before its full discharge. The main thing is not to overload the electric screwdriver itself, so that it does not have to repair it in the future. This charging/discharge procedure must be repeated several times in a row.
In the same way, approximately every three months, it is recommended to carry out the procedure to erase the “memory effect”, which will extend the operation of the battery and the electric screwdriver itself.
Step.By.Step repair instructions
At home, you can independently reanimate the battery of an electric screwdriver. To do this, open the battery housing and replace the elements (or in other words. Cans).
DIY: How to revive a dead 18650 (or any) Li-ion battery cell
How to disassemble the battery housing
The battery of most screwdrivers has a collapsible housing. But some manufacturers to prevent independent replacement of elements make the battery housing indefatigable. Thus, they force the owner to purchase a new company battery. In this case, to disassemble the case without its irreversible damage will be very difficult.
The connection of the parts of the case can be made using screws, a latch or glue. In the first case, you can divide the parts of the case by simply twisting the screws with a screwdriver.
If the parts of the case are glued, it is necessary carefully with the help of a knife, push the details, sticking the blade into it. Then you need to split the joint, inserting any solid object in the formed gap that is suitable in size. After you need to move around the entire perimeter of the case. After the case is disassembled, its parts will need to be put again on glue.
We find faulty cells
After the case is open, you can see that the elements of the battery are interconnected. In order to repair the battery for an electric screwdriver, you will need to determine a faulty element. Usually it is one or two elements. And replace it.
Long.Term soldering cannot be used, since you can ruin the element if it is heated. Lithium-ion batteries are especially sensitive to heating. If there is no experience of soldering such batteries, you can purchase batteries with already weld contacts on AliExpress.
On the Internet they write that nickel-cadmium batteries dry over time and the element (jar) can be restored-drill the hole in it and with the help of a syringe pour inside the water. But this method of recovery can lead to damage to the element and even to injury, so we will not consider it.
In order to find faulty elements, it is required to check what voltage each element of the battery produces separately.
For the work of accurate measurements, it is necessary that the battery is completely charged.
It is necessary to extract the contents of the case and lay out all the elements on the flat surface. It will be much easier to measure voltage if you provide free access to each contact of the battery element.
For convenience, you should draw a circuit on a sheet of paper and mark on it the voltage of each element. The voltage measurement is carried out using a multimeter, having previously selected a mode of measurement of a constant voltage with a low measurement limit.
The voltage level for each nickel-cadmium element should be from 1.2 to 1.4 V, and for lithium-ion elements-from 3.6 to 3.8 V.
Then the battery should be discharged. To do this, you can connect the load to it. For example, a large.Power incandescent lamp or you can assemble a battery and work with an electric screwdriver until it is discharged.
After that, the battery is disassembled again and voltage is measured. If the voltage losses were previously determined on the elements, with the repeated measurement, the multimeter readings will be even lower. It should be replaced by elements where the difference in voltage readings will be significant: up to 0.5 or 0.7 V for cadmium and less than 2.5 volts for lithium.
If the battery is very worn out, then even after prolonged charging on separate batteries the voltage will be significantly lower than the rest (sometimes completely close to 0 volts). They need to be changed, they are unlikely to be restored.
Selection of elements for replacement
Choose batteries Li-Ion (lithium-ion) or ni-cd (nickel-cadmium) elements for replacement in several ways. If there are several faulty batteries from one electrical screwdriver, you can find workers by dismantling them, or find them in electrical goods stores, or on online stores, for example, on AliExpress. As a rule, manufacturers of the main brands of screwdrivers use models of lithium batteries produced by several manufacturers.
Also on AliExpress you can buy the necessary elements of the battery with additional contacts already welded using contact welding. This will greatly simplify the replacement process and reduce the likelihood of damage to the replaced element.
Pay attention to the compliance of the technical characteristics of the replaced elements, especially the capacity and voltage.
How to solder banks to a battery
If there is experience in soldering radio components, then replacing the damaged nutrition element (banks) will not cause difficulties:
- Gently disconnect the damaged element by cutting the connecting plate. When replacing the element, follow the polarity;
- Then you need to solder the elements among themselves. Pay attention to the time of heating of the contact-it should be minimal, which is especially important for lithium-ion batteries. With prolonged contact, such an element will inevitably fail, and can also selflessly or explode. Therefore, the movement when soldering should be accurate and very fast;
- After all the elements are reliably soldered, you need to collect them and fasten them together with tape or insulating tape. The assembly process is similar to disassembly, but in the reverse order. After assembly, the contents are laid in the case, and the cover is fixed with screws or with glue.
What is the problem during the operation of Ni─CD batteries?
During the operation, Ni─CD is gradually reduced voltage and discharge capacity. Below are the main factors that determine these processes:
- Reduction of the working surface of positive and negative electrodes;
- Loss of active mass, as well as its redistribution by electrodes;
- The occurrence of current leaks due to the formation of the dendrites of the metal CD;
- Processes as a result of which irreversible consumption of water and oxygen occurs;
- Changing the composition and volume of electrolyte.
Similar processes occur when ni-mh batteries are operated. The difference only in the materials used by the electrodes.
During the operation of the Ni─CD batteries due to the redistribution of the active mass through the electrodes, the mechanical strength and volume of oxide-nickel (positive) electrode are changed. As a result, contact m/a active mass and electrode worsens. All this causes a decrease in conductivity and falling capacity. In the neglected version, the contact between the positive and negative electrodes simply breaks. As a result, the battery ceases to show signs of life.
All these changes in the oxythly ─ electrode are caused by constant overheads, in which oxygen release process in the space of a positive electrode. The more batteries the charge of the charge cycles passes, the more the enlargement of the crystals of the active mass of the positive electrode is observed. Therefore, the working surface is reduced, and, therefore, the capacity of the battery.
On the cadmium electrode, the process of degradation is determined mainly by the migration of the active mass. As a result, some of its loss occurs. In addition, the active mass clogs pores in the surface layer of the negative electrode. Because of this, the electrolyte access to the deep layers is difficult. The result of the migration of active mass is the growth of dendritic bridges through the separator to a positive electrode. These leads to numerous short micro.Loading and increases self.Discharge. During operation, crystals and an increase in the volume of active mass also occur on the cadmium electrode during operation.
In addition to the above processes, the ni─CD batteries occur processes of oxidation of various additives that are present in the battery. The cermaramics of the positive electrode are gradually oxidized with water consumption. And another unpleasant process that leads to the loss of operability of the NI─CD battery, is the selection of an electrolyte from the separator. This is due to a change in the porous structure of the electrodes and leads to an increase in the internal resistance of the nickel-cadmium battery. The composition of the electrolyte also changes during operation. In particular, the volume of carbonates is growing. The electrolyte electrolyte is reduced and all the Ni─CD battery parameters fall during discharge. The picture becomes especially noticeable at low temperatures. What to do in such cases?
Complete replacement and erasing of the “memory” of batteries
In rare cases, for example, if the battery is too old, then all the elements come out of the system. Buying a new battery will be more expensive than replacing all cans. Therefore, it makes sense to order separate power sources through the Internet, to solder them in the battery, and then put them in the old case.
There is a small secret to extending the service life of new power sources. To do this, you need to remove the factory settings from the cans, which are installed by several cycles of the charge/category. The operation to extend durability should only be carried out on new elements, and in the future they are correctly charged.
The new battery jar is discharged to a voltage of 1 in. It is important to monitor this parameter, since the battery can become unusable below one volt, after which its restoration will be impossible. For discharge, it is best to use the adjustable load on which set current 1 a.
After complete discharge, all elements must be reached, using the nominal indicators of current and voltage for this. After a full charge, you can solder power sources in the battery and install on a screwdriver.
What you need to know before starting the restoration of the screwer of the screwdriver?
Most of the power elements in the power tool have the same design features (sequential connection of compact cells). 2. It is necessary to pay attention to the type of battery (Ni-CD, Ni-MH and Li-Ion) and capacity (in mAC). 3. When disassembling the battery block, the polarity (/-) of the compounds must be monitored. 4. From overheating the “banks” are protected by the termistor with a soldered resistor. 5. It is impossible to restore an element of power li-ion (how to determine its serviceability, see below).
Charge the battery to full level, remove from charging and disassemble for access to cells. 2. Using a multimeter, measure the voltage (in DCV mode) of each cell (battery). 3. In good condition, Ni-CD and Ni-MH give out 1.2-1.4 V, and Li-Ion-3.6-3.8th century. 4. Gather the battery and discharge it until a clear slowdown in rotation of the screwdriver. 5. Disassemble and measure again. Reduction of voltage to level 0.4-0.8 in says the wear of such a cell.
Repair of the battery of an electric screwdriver
Good day.I decided to share my experience in repairing the battery for an electric screwdriver.Give me it on DR in 2008. There were two batteries in the sets.
He used it episodically and shortly, but noticed that a fully charged battery is discharged to zero for a week, even if they do not use it.Every year it is worse, and this year there was only a completely charged battery for only five minutes of work. And such nonsense with both batteries.Disorder!I dismantled both batteries. Inside were the batteries a little thicker of the finger, more than half of which did not show signs of life. It was not possible to collect one of the two batteries, t.To. Than half of the elements failed.Went to the store- and there are no such batteries in stock. Similar are from a thousand.Since an electric screwdriver is 12 volts, I decided to buy an acid sealed battery for 1.2 ah.
To the contacts of the upper part of the case, the wire with the connectors.Checked the electric screwdriver works.Now the most difficult. Put the battery into the case.I tried to put it in the corps does not impose.Cut off all partitions. Does not impose.Cut the opening in the upper part- halves do not close.
He sawed the groove for the wire in the upper half of the hollow.I had to cut the opening at the bottom.
Glued the battery to the lower part of thermoclay
Half knew a black island to each other, just in case, suddenly it would be necessary to disassemble.
Bottom line: working electric screwdriver. Costs- half an hour and 300
UPD: There were many questions about charging. Disassembled his:
My charging is elementary: a diode bridge and a current.Limiting (ballast) resistor. Well, plus for the LED resistor. The adapter says the maximum current of 400 mA, but in fact the initial current is less, possibly due to a higher battery resistance. The ammeter shows 350-320 mA. The battery says the maximum charging current-360 mA. And since the charging is not automatic, you need to sit on time and turn off the charging.If your charge is larger in your charge, you need to increase the ballast resistor.
If your charging is automatic, with a large initial charging current, then it is not suitable for lead-acid batteries, t.To. There is a danger of the “destruction” of the battery (destruction can be accompanied by an acoustic blow, splashes of acid, whistle of fragments, caustic smoke and other troubles).
UPD from 23.01.2021s of the past 5 years have passed some changes. Report: 1. The battery in 4 years has lost its capacity. Went to the store- bought 350 new. Change- 5 minutes you need. I didn’t even have to drink anything. The hardest thing was to dig.2. Integrated into charging voltmeter-ammeter, for clarity of the charging process.
During operation, the wire frayed at the charging plug, the wires were injected and the power supply fell the death of the brave in the fight against overheating). I did not find the same power supply. I bought in China the simplest charging for lead batteries, and it gives too much current. I had to integrate current stabilizer. Set up 300 m. Now you can leave calmly at night. When turning on, the maximum current is limited, upon reaching 14 in charging will be disconnected. Come up with only how to make wires carefully.
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