Alteration Of The Battery Of The Screwdriver 14 4 Volts
The design of a lithium rechargeable battery is not too different from the design of batteries based on other chemistry. But the fundamental feature is the use of anhydrous electrolyte, which prevents the release of free hydrogen during operation. This was a significant disadvantage of the batteries of the previous designs and led to a high probability of fire.
The anode is made of a cobalt oxide film deposited on an aluminum base-current collector. The cathode is the electrolyte itself, which contains lithium salts in liquid form. The electrolyte impregnates a porous mass of electrically conductive chemically neutral material. Loose graphite or coke is suitable for it. Current collection is carried out from a copper plate superimposed on the back of the cathode.
For normal battery operation, the porous cathode must be pressed tightly enough to the anode. Therefore, in the design of lithium batteries, there is always a spring that compresses the “sandwich” from the anode, cathode and negative current collector. The ingress of ambient air can upset the carefully balanced chemical balance. And the ingress of moisture and does threaten the danger of fire and even explosion. Therefore, the finished battery cell must be carefully sealed.
A flat battery is simpler in design. All other things being equal, a flat lithium battery will be lighter, much more compact, and provide significant current (that is, more power). But it is necessary to design a device with flat-shaped lithium batteries, which means that the battery will have a narrow, specialized application. Such batteries are more expensive than their counterparts.
To make the sales market wider, manufacturers produce battery cells of universal shape and standard sizes.
Among lithium batteries, the 18650 version actually dominates today. Such batteries have a look similar to the cylindrical finger-type batteries familiar in everyday life. But the 18650 standard specifically provides for a slightly larger size. This avoids confusion and prevents such a power supply unit from being mistakenly replaced in place of a conventional saline battery. But this would be very dangerous, since the lithium battery has two and a half times the standard voltage (3.6 volts versus 1.5 volts for a salt battery).
For an electric screwdriver, lithium cells are sequentially collected into a battery. This allows the voltage to the motor to be increased to provide the power and torque required by the tool.
The rechargeable battery necessarily contains in its design temperature sensors and a specialized electronic device. a controller.
- monitors the uniformity of the charge of individual elements;
- controls the charge current;
- does not allow excessive discharge of elements;
- prevents overheating of the battery.
Batteries of this type are called ionic. There are also lithium-polymer cells, this is a modification of lithium-ion. Their design is fundamentally different only in the material and design of the electrolyte.
Features, advantages and disadvantages of lithium batteries for screwdriver
- Advantages and disadvantages
- Difference from nickel cadmium batteries
- How to choose?
- How to remake and assemble?
- How to charge correctly?
- How to store?
If a hand-held power tool powered by a household power supply is tied to an outlet with a wire, limiting the movements of a person holding the device in his hands, then battery-operated counterparts of the units “on a leash” provide much more freedom of action in work. A battery is essential when it comes to using screwdrivers.
Depending on the type of battery used, they can be conditionally divided into two groups. with nickel and lithium batteries, and the features of the latter make this power tool the most interesting for the user.
Difference from nickel cadmium batteries
Historically, the first truly mass-produced rechargeable batteries for handheld power tools were nickel-cadmium batteries. At a low price, they are quite capable of relatively high loads and have a satisfactory electrical capacity with reasonable dimensions and weight. Batteries of this type are still widespread today, especially in the low-cost handheld appliance sector.
The main difference between lithium batteries and nickel-cadmium batteries is low weight with high electrical capacity and very good load capacity.
In addition, a very important difference between lithium batteries is the significantly shorter charging time. This battery can be charged in a couple of hours. But the full charge cycle of nickel-cadmium batteries takes at least twelve hours.
There is another peculiarity associated with this: while lithium batteries tolerate both storage and operation in an incompletely charged state quite calmly, nickel-cadmium batteries have an extremely unpleasant “memory effect”. In practice, this means that in order to extend the service life, as well as to prevent a rapid loss of capacity, it is advisable to use nickel-cadmium batteries until they are completely discharged. After that, be sure to charge to full capacity, which takes a considerable time.
Lithium batteries do not have this disadvantage.
Advantages and disadvantages
- The main advantage of lithium batteries is their high electrical capacity. This allows you to create a lightweight and compact hand tool. On the other hand, if the user is ready to work with a heavier device, he will receive a very powerful battery that allows the screwdriver to work for a long time.
- Another advantage is the ability to fill lithium batteries with energy relatively quickly. A typical full charge time is approximately two hours, and some batteries can be recharged in half an hour with a special charger! This advantage can be an exceptional reason for equipping a screwdriver with a lithium battery.
Lithium batteries also have some specific disadvantages.
- The most noticeable is the significant drop in practical capacity when working in cold weather. At subzero temperatures, an instrument equipped with lithium batteries has to be warmed up from time to time, while the electrical capacity is fully restored.
- The second noticeable drawback is not too long service life. Despite the assurances of the manufacturers, the best samples, with the most careful use, withstand no more than three to five years. Within a year after the purchase, a lithium battery of any common brand, with the most careful use, can lose up to a third of its capacity. After two years, hardly half of the original capacity will remain. Average life of normal operation is two to three years.
- And another notable drawback: the price of lithium batteries is much higher than the cost of nickel-cadmium batteries, which are still widely used in handheld power tools.
How to remake and assemble?
Often, the master already has an old cordless screwdriver that suits him completely. But the device is equipped with outdated nickel-cadmium batteries. Since the battery will still have to be changed, there is a desire to replace the old battery with something newer. This will not only provide more comfortable work, but also eliminate the need to look for older batteries on the market.
The simplest thing that comes to mind is to assemble a power supply from an electronic transformer in an old battery case. Now you can use the screwdriver by connecting it to the household power supply.
Models with a voltage of 14.4 volts can be connected to car batteries. Having assembled an extension adapter with terminals or a cigarette lighter plug from the body of an old battery, you get an indispensable device for a garage or work “in the field”.
Unfortunately, when converting an old battery into a wired adapter, the main advantage of the cordless screwdriver is lost. mobility.
If we are converting an old battery to lithium, we can take into account that 18650 lithium cells are extremely widespread in the market. Thus, we can make screwdriver batteries based on readily available parts. over, the prevalence of the 18650 standard allows you to choose batteries from any manufacturer.
It will not be difficult to open the case of an old battery and remove the old filling from it. It is important not to forget to mark the contact on the case to which the “plus” of the old battery assembly was previously connected.
Depending on the voltage for which the old battery was designed, it is necessary to select the number of lithium cells connected in series. The standard voltage of a lithium cell is exactly three times that of a nickel cell (3.6 V instead of 1.2 V). Thus, each “lithium” replaces three series-connected “nickels”.
By providing for the design of the battery, in which three lithium cells are connected one after the other, it is possible to obtain a battery with a voltage of 10.8 volts. Among the nickel batteries, these are found, but not often. When four lithium cells are connected to a garland, we already get 14.4 volts. This will replace both 12 volt and 14.4 volt nickel batteries. these are very common standards for nickel cadmium and nickel metal hydride batteries. It all depends on the specific model of the screwdriver.
After it was possible to determine the number of successive stages, it will probably turn out that there is still free space in the old building. This will allow two cells to be connected in parallel in each stage, which will double the battery capacity. To connect lithium batteries to each other in production, a nickel strip is used. Segments of tape are connected to each other and to lithium elements by resistance welding. But in everyday life, soldering is quite acceptable.
Soldering lithium cells should be done with great care. The joint must be thoroughly cleaned beforehand and a good flux must be applied. Tinning is done very quickly, with a well-heated soldering iron of sufficiently high power.
The soldering itself is performed by quickly and confidently warming up the place where the wire is connected to the lithium cell. To avoid dangerous overheating of the element, the soldering time should not exceed three to five seconds.
When designing a homemade lithium battery, you should take into account that it is charged in a special way. It is imperative to provide an electronic circuit for monitoring and balancing the charge in the design of the battery. In addition, such a circuit should prevent possible overheating of the battery and excessive discharge. Without such a device, a lithium battery is simply explosive.
It is good that now there are ready-made electronic control and balancing modules on sale at fairly low prices. It is enough to choose the solution that suits your particular case. Basically, these controllers differ in the number of series-connected “steps”, the voltage between which is subject to equalization (balancing). In addition, they differ in their permissible load current and temperature control method.
In any case, it is no longer possible to charge a homemade lithium battery with an old nickel battery charger. They have fundamentally different charging algorithms and control voltages. You will need a dedicated charger.
How to charge correctly?
Lithium batteries are quite finicky about charger specifications. Such batteries can be charged fairly quickly with a significant current, but excessive charging current leads to severe heating and fire hazard.
To charge a lithium battery, it is imperative to use a special charger with electronic control of the charge current and temperature control.
It should also be borne in mind that when cells are connected in series in a battery, lithium sources are very prone to uneven charging of individual cells. This leads to the fact that it is not possible to charge the battery to its full capacity, and the element, which regularly works in undercharged mode, simply wears out faster. Therefore, chargers are usually built according to the “charge balancer” scheme.
Fortunately, all modern factory-made lithium batteries (except for outright fakes) have built-in protection and balancing circuits. However, the charger for such batteries must be specialized.
How to choose?
When it comes to choosing a battery for a screwdriver, the task comes down to the selection of the electrical device itself, complete with which there will be a battery of a specific model.
The rating of inexpensive cordless screwdrivers this season looks like this:
- Makita HP331DZ, 10.8 volts, 1.5 Ah, lithium;
- Bosch PSR 1080 LI, 10.8 volts, 1.5 Ah, lithium;
- Bort BAB-12-P, 12 volt, 1.3 Ah, nickel;
- Interskol DA-12ER-01, 12 volts 1.3 Ah, nickel;
- Kolner KCD 12M, 12 volt, 1.3 Ah, nickel.
The best professional models are:
- Makita DHP481RTE, 18 volts, 5 Ah, lithium;
- Hitachi DS14DSAL, 14.4 volts, 1.5 Ah, lithium;
- Metabo BS 18 LTX Impuls 201, 18 volt, 4 Ah, lithium;
- Bosch GSR 18 V-EC 2016, 18 volts, 4 Ah, lithium;
- Dewalt DCD780M2, 18 Volt 1.5 Ah, lithium.
The best cordless screwdrivers in terms of reliability:
- Bosch GSR 1440, 14.4 volts, 1.5 Ah, lithium;
- Hitachi DS18DFL, 18 Volt, 1.5 Ah, Lithium
- Dewalt DCD790D2, 18 Volt, 2 Ah, Lithium.
You can see that the best screwdrivers in the semi-professional and professional segments have 18-volt rechargeable batteries.
This voltage is considered the industry professional standard for lithium batteries. Since a professional tool is designed for long-term active work, and also implies an additional level of comfort, a significant part of the produced 18-volt screwdriver batteries are fully compatible with each other, and sometimes even interchangeable between tools from different manufacturers.
In addition, the 10.8 volt and 14.4 volt standards are widely used. The first option is found only among the most inexpensive models. The second is traditionally “middle peasant” and can be found both among professional models of screwdrivers and in models of the middle (intermediate) class.
But the designations of 220 volts in the characteristics of the best models cannot be seen, since this indicates that the screwdriver is connected with a wire to a household power outlet.
How to disassemble a screwdriver battery
How to disassemble an old battery? There are batteries where the halves of the case are fastened with screws, but there are also glue ones. My batteries are just the latest ones, and for a long time I generally believed that they could not be disassembled. It turned out that it is possible if you have a hammer.
In general, with the help of intense blows to the perimeter of the edge of the lower part of the case (a hammer with a nylon head, the battery must be held in the hand by weight), the gluing site is successfully disconnected. At the same time, the case is not damaged in any way, I have already disassembled 4 pieces this way.
The part of interest to us.
From the old circuit, only contact plates are needed. They are permanently spot welded to the upper two elements. You can pick out the welding with a screwdriver or pliers, but you need to pick it as carefully as possible so as not to break the plastic.
Everything is almost ready for further work. By the way, I left the standard thermal sensor and disconnector, although they are no longer particularly relevant.
But it is very likely that the presence of these elements is necessary for the normal operation of a standard charger. Therefore, I highly recommend saving them.
Converting the battery of the screwdriver to Li-Ion
I won’t say anything new in this article, but I just want to share the experience of upgrading the batteries of my old Makita screwdriver. Initially, this tool was designed for nickel-cadmium batteries (which have long since died, just as those bought for replacement have died). The disadvantages of Ni-Cd are well known: low capacity, short lifespan, high price. Therefore, cordless tool manufacturers have long since switched to lithium-ion batteries.
Well, what about those who have an old instrument? Everything is very simple: throw away the Ni-Cd cans and replace them with Li-Ion of the popular 18650 format (the marking indicates the diameter is 18 mm and the length is 65 mm).
What board is needed and what elements are needed to convert a screwdriver to lithium-ion
So here’s my 9.6V 1.3 Ah battery. At the maximum charge level, it has a voltage of 10.8 volts. Lithium-ion cells have a nominal voltage of 3.6 volts, the maximum voltage is 4.2. Therefore, to replace the old nickel-cadmium cells with lithium-ion ones, I need 3 cells, their operating voltage will be 10.8 volts, the maximum is 12.6 volts. Exceeding the rated voltage will not damage the motor in any way, it will not burn out, and with a larger difference, there is no need to worry.
Lithium-ion cells, as everyone has known for a long time, categorically do not like overcharging (voltage above 4.2 V) and excessive discharge (below 2.5 V). When the operating range is exceeded, the element degrades very quickly. Therefore, lithium-ion cells always work in tandem with an electronic board (BMS. Battery Management System), which controls the cell and monitors both the upper and lower voltage limits. This is a protection board that simply disconnects the can from the electrical circuit when the voltage goes out of the operating range. Therefore, in addition to the elements themselves, such a BMS board will be required.
Black & Decker 6 Volt Cordless Screwdriver
Now there are two important points that I experimented with unsuccessfully several times until I came to the right choice. This is the maximum permissible operating current of the Li-Ion cells themselves and the maximum operating current of the BMS board.
In a screwdriver, operating currents at high loads reach 10-20 A. Therefore, you need to buy elements that are capable of delivering high currents. Personally, I have successfully used 30-amp 18650 cells from Sony VTC4 (2100 mAh capacity) and 20-amp Sanyo UR18650NSX (2600 mAh capacity). They work fine in my screwdrivers. But, for example, Chinese TrustFire 2500 mAh and Japanese light green Panasonic NCR18650B 3400 mAh are not suitable, they are not designed for such currents. Therefore, there is no need to chase the capacity of the elements. even 2100 mAh is more than enough; the main thing when choosing is not to miscalculate with the maximum permissible discharge current.
Likewise, the BMS board must be rated for high operating currents. I saw on Youtube how people collect batteries on 5 or 10-ampere boards. I don’t know, personally, when I turned on the screwdriver, such boards immediately went into defense. In my opinion, this is a waste of money. I will say that Makita itself puts 30-ampere boards in its batteries. Therefore, I use 25-amp BMS bought from Aliexpress. They cost about 6-7 and are searched for “BMS 25A”. Since you need a board for an assembly of 3 elements, you need to look for such a board, in the name of which there will be “3S”.
Another important point: some boards have different contacts for charging (designation “C”) and load (designation “P”). For example, a board can have three pins: “P-“, “P” and “C-“, as on the native Makitov lithium-ion board. Such a fee will not work for us. Charging and discharging (charge / discharge) must be done through one contact! That is, there should be 2 working contacts on the board: just “plus” and just “minus”. Because our old charger also only has two pins.
In general, as you might have guessed, with my experiments I threw out a lot of money both on the wrong elements and on the wrong boards, having made all the mistakes that could be made. But I got invaluable experience.
Makita DC9710 charger and lithium-ion battery
Previously, the battery was controlled by the device itself. When the full level was reached, it stopped the process and signaled the completion of charging with a green indicator. But now the BMS circuit we have installed is engaged in level control and power off. Therefore, when charging is complete, the red LED on the charger will simply turn off.
If you have such an old device, you’re in luck. Because everything is simple with him. The diode is on. charging is in progress. Off. charging completed, battery fully charged.
Putting together a lithium-ion battery
Here are the new elements of Sanyo UR18650NSX (according to this article they can be found on Aliexpress) with a capacity of 2600 mAh. For comparison, the old battery had a capacity of only 1300 mAh, half the size.
It is necessary to solder the wires to the elements. The wires must be taken with a cross section of at least 0.75 sq. Mm, because we will have considerable currents. A wire with such a cross section normally works with currents of more than 20 A at a voltage of 12 V. You can solder lithium-ion cans, short-term overheating will not harm them in any way, this has been verified. But you need a good fast-acting flux. I use TAGS glycerin flux. Half a second. and you’re done.
We solder the other ends of the wires to the board according to the diagram.
I always put even thicker wires of 1.5 mm2 on the battery contacts. because the space allows. Before soldering them to the mating contacts, I put a piece of heat-shrink tubing on the board. It is necessary for additional isolation of the board from battery cells. Otherwise, the sharp edges of the solder can easily rub or puncture the thin film of the lithium-ion cell and cause a short. It is possible not to use heat shrinkage, but at least something insulating to be laid between the board and the elements is absolutely necessary.
Now everything is insulated as it should.
The contact part can be fixed in the battery case with a couple of droplets of super glue.
The battery is ready for assembly.
It’s good when the case is on the screws, but this is not my case, so I just glue the halves again “Moment”.
The battery is charged with a standard charger. True, the algorithm of work is changing.
I have two chargers, DC9710 and DC1414 T. And they work differently now, so I’ll tell you exactly how.
Makita DC1414 T charger and lithium-ion battery
There is a small nuance here that you need to know. This charger is newer and is designed to charge a wider range of batteries from 7.2 to 14.4 V. The charging process on it goes as usual, the red LED is on:
But when the battery (which in the case of NiMH cells is supposed to have a maximum voltage of 10.8 V) reaches 12 volts (we have Li-Ion cells with a maximum total voltage of 12.6 V), the charger will blow the roof. Because he will not understand what kind of battery he is charging: either 9.6-volt, or 14.4-volt. And at this moment Makita DC1414 will enter error mode, alternately blinking red and green LEDs.
This is normal! Your new battery will still charge. though not completely. The voltage will be approximately 12 volts.
That is, you will miss some part of the capacity with this charger, but it seems to me that you can survive.
In total, the upgrade of the oBosch battery cost about 1000 rubles. Makitov’s new Makita PA09 costs twice as much. over, we ended up with twice the capacity, and further repair (in the case of a slight failure) will consist only in replacing lithium-ion cells.
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Alteration of the battery of the screwdriver 14 4 volts
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Indicator for charging a screwdriver 14.4 volts
I bought a cheap Chinese SKIL-2007 screwdriver, a battery of 14.4 V. 1.2A / h, in principle, you can work normally, but it had two drawbacks. First. there is no adjustment of the rotation speed, I coped with it quickly, I put a switch with a speed regulator Second, there is no indicator of the end of charging. The set includes two batteries and a simple charger made in two separate parts. In a small case, which is plugged into an outlet, there is a transformer with a rectifier, it gives out 18 V 200 mA at the output, a piece of wire with a connector leaves from it. The second part of. the charger itself with indicators, here is its diagram. fig. 1.
A green LED indicates that the device is online. Red indicates that the battery is charging, it will remain lit as long as the battery is connected to the charger. According to the mat, the charge time is 3-5 hours. Since it is impossible to control the end of charging with this charger, I decided to add my own. Searches on the Internet did not give anything, they came across too abstruse on the controllers, the program to which is sent for a separate fee, or the schemes according to which the charge is determined by the brightness of the LED glow, but this is also not the best option, since during the day in sunlight the brightness seems small, but in the dark big.
I decided to make a simple, reliable battery charging indicator from available parts. I took a car voltage indicator as a basis (found on the shelves in the garage), they are still on sale, it is a cylindrical body that is plugged into the car’s cigarette lighter, at the end there are three LEDs arranged in a row, red at the edges, green in the middle. Here is its diagram (Fig. 2.) and passport data.
- red LED VD3. 12V;
- green LED VD4. 12.5 to 14.5 V;
- red LED VD4. more than 15 V.
- red VD3 and green VD4. 12.0 to 12.5 V;
- red VD2 and green VD4. 14.5 to 15.0 V.
This circuit will work without modification for a 12-volt screwdriver. Does not contain scarce parts and can be easily assembled by a novice radio amateur.
In my screwdriver, the voltage of a fully charged battery while charging is 16.5. 16.8 V, it will not rise higher, although it will charge for a day. The alteration of the car indicator is as follows: the case is disassembled and thrown out, leaving a 16×38 board with three LEDs. Zener diode VD1, replaced by D814G, instead of R2, set a variable resistor of 1 kOhm.
Setting: a power supply with an adjustable voltage of up to 20 V is connected to the input “±” of the indicator. We set a voltage of 16.5 V at the output of the power supply and by rotating the variable resistor slider we achieve that only the green LED is on, as soon as the red VD3 goes out, the rotation stops. This completes the setup.
I got the following charging values: Red VD3. up to 15 V (battery discharged). Red VD3 and green VD4. 15.16.5V (50-80% charged).
Green VD3. 16.5. 19.3 (100% charged). Red VD2. more than 19.3V (this indicator is practically not used).
Then, instead of a variable resistor, set a constant one, in my case it turned out R2 = 470 Ohm, but you can leave the construction one. the indicator is connected to the standard charger to the “±” terminals of the battery. Three holes are drilled in the case for the LEDs and the indicator is inserted into the case of the charger, there is a lot of space there, and it is fixed. Everything native remains in its place.
When you turn on the charger without a battery, VD2 lights up. We insert the discharged battery into the charger, VD2 goes out, the VD3 indicator lights up, as the charging voltage reaches 15 V, the green indicator VD4 starts to light up, and the brightness of VD3 decreases and finally VD3 goes out red, and the green VD4 lights up with full glow, charging can be considered completed.
As a result of this addition to the charger, charging, instead of 3-5 hours according to the passport, ends much earlier. At any time, by the glow of the indicators, you can determine at what stage the battery being charged is. According to the tuning method, this circuit is also suitable for other chargers, for a different voltage. To do this, the battery is fully charged, as stated in the instructions for 3-5 hours, then without removing the battery from the charger, the voltage of the fully charged battery is measured. This voltage is set at the output of the regulated power supply and by selecting the Zener diode VD1 and the resistor R2, they achieve a clear operation of the indicator, as indicated above.
See other articles of the section Chargers, batteries, galvanic cells.
Read and write helpful comments on this article.
Comments on the article:
And where in the VD4 circuit?
It feels like the diagram was drawn by one, and the article was written by another person.
The alteration scheme is not bad, but there are many inaccuracies and confusion in the description.
Battery case power supply
Mobility remains, you are limited only by the length of the network cable. The only problem is how to squeeze a sufficiently powerful transformer into a small case.
We recall Ohm’s law again, and we understand that a powerful 220 volt electric motor can be compact.
Making a homemade power supply
If you are familiar with the principles of building electrical circuits, you can make your own power supply. Scheme giving general concepts. in the illustration.
The transformer can be picked up from an old tube TV, or other household appliances. Power 220 volts 250-350W. The main thing is the power supply. the donor should not be pulsed.
The voltage on the secondary winding is 24-30 volts. The secondary winding is made from a wire of the corresponding section.
However, if the output winding current is at least 15 amperes (see transformer specification), there is nothing to worry about.
After losses on the diode bridge (1-1.5 V on the diode), you will get the required output value.
If you have an electrical engineering education, make the calculation yourself. Or in a practical way: by connecting a 220 volt 100W incandescent lamp as a load, measure the output voltage. E
If it exceeds the needs of the screwdriver, reduce the number of turns of the secondary winding of the transformer.
Conversion of a screwdriver from a battery to a mains supply
- Battery Disadvantages
- There is a way out. reworking the screwdriver in the network
- External power supply
- Battery case power supply
- DIY screwdriver alteration
- Using a power supply from a personal computer
- Using a car battery charger
- Making a homemade power supply
- AC adapter for screwdriver in battery housing
- We build in a ready-made power supply
- Homemade power scheme
Those who have used a cordless screwdriver have appreciated its convenience. At any time, without getting tangled in the wires, you can crawl into hard-to-reach niches. Until the battery runs out.
There is a way out. reworking the screwdriver in the network
Yes, it loses one of the benefits of a cordless tool. mobility. But for work in rooms with access to a 220 volt network, this is an excellent way out. Especially since you give new life to a broken instrument.
There are two concepts of how to make a network out of a cordless screwdriver:
We build in a ready-made power supply
To do this, you need to purchase a ready-made block with suitable characteristics and dimensions. There is enough such good on the radio markets.
Take the body with you and go to the fitting. When the desired power source is purchased, carefully separate it from the case.
We place the screwdriver in the battery box. All components must be securely fastened.
If necessary, extend the wires connecting the control board and the transformer. If the circuit touches the metal parts of the transformer during operation, a short circuit will occur.
Since the space in the case allows. separate the board and the transformer for better cooling. Whichever quality power supply you choose, the load will be high and overheating is possible.
It will not be superfluous to fix additional radiators on the power control microcircuits. Operate the screwdriver for a long time, disconnect it from the mains and touch the radio parts on the control board.
You yourself will understand which elements need heat dissipation. Holes can be made in the housing for air circulation.
Redesigning the power supply unit with your own hands will not take much time, and the cost of the purchased module is incomparable with restoring the battery’s performance.
- Needs regular recharging. Sooner or later, batteries will run out of charge cycles.
- The cheaper the tool, the faster the rework time will come.
There is nothing wrong with that, but you should be aware that the manufacturer saves as much as you do. Therefore, the most expensive unit (and this is the battery) will be the cheapest when bundled.
As a result, we get an excellent tool with a serviceable motor and not a worn gearbox, which does not work due to a poor-quality battery.
There is an option to purchase a new set of batteries, or replace faulty batteries in the unit. However, this is a budget event. The cost is comparable to buying a new screwdriver.
The second option is to use a spare or old battery from the car (if you have one). But the starter battery is heavy, and the use of such a tandem is not very comfortable.
Using a car battery charger
The principle is the same as using a computer power supply. It is necessary to purchase an old charger for the starter batteries The modern fashion for compact impulse chargers has left analog linear devices with manual adjustment of voltage and charge current behind board. Therefore, such a device can be purchased on the automotive market for a symbolic cost.
Charger MAX INTER
It’s good if the voltage can be adjusted smoothly. in this case, your makeshift power supply will fit any screwdriver.
Converting it to a power tool is reduced to connecting the input of the electric motor to the power terminals of the charger.