How to convert a cordless screwdriver into a corded one - options for craftsmen. Selecting a screwdriver based on voltage and other parameters. What current does the screwdriver produce?

22.10.202327.05.2017

One of the most common tools among craftsmen is a screwdriver. In terms of popularity, it is perhaps located right behind the drill, although it includes some of its functions. The main purpose of this tool is to screw in screws, or rather, to screw in self-tapping screws.

Let's look at the basic requirements that need to be taken into account when choosing a screwdriver. They are divided into two main types, namely network ones, operating from a 220 volt household network, and rechargeable ones, respectively, operating from a battery. Since networked ones are not very common, we will not consider them specifically, but will only say that many selection parameters automatically become relevant for networked screwdrivers.

How many volts should a screwdriver be? The battery voltage of a screwdriver directly affects its power. From the school physics course we know that power is equal to the product of voltage and current. It follows from this that the higher the operating voltage of the battery, the higher the power of the device. Of the screwdrivers on the market, the most common battery voltages are 6, 12, 18, 24 and 36 volts. This voltage is always indicated by the manufacturer on the product label.

How many watts should a screwdriver be? This issue was partially covered in the previous paragraph. But it’s worth summing up: the more powerful the screwdriver, the more comfortable it is to work with it. It is worth considering that the power of the device must match the battery. The battery power must be designed for the energy consumption of the motor that is built into the screwdriver. If the ratios are incorrect, you can end up with rapid battery drain. It should also be noted that the more powerful the device and the more powerful the power source, the higher the weight and dimensions of the tool. Well, as a consequence - a higher price for a screwdriver. If we consider battery power, then it is most likely more correct to say not power, but battery capacity. It is measured in ampere hours and designated as Ah.

Read also: Which thermostat to buy for heated floors

Screwdriver, which battery to choose? Three types of maintenance-free batteries are common in household appliances and tools: nickel-cadmium (Ni-Cd), nickel-metal hydride (Ni-MH) and lithium-ion (Li-Ion). The first and second have a huge drawback - memory. Over time, these types of batteries begin to charge and not fully discharge. This leads to a loss of power from the element, or simply put, to the loss of our precious ampere-hours. In addition, the average number of charge-discharge cycles is 1000 cycles. If the tool is used intensively, the batteries will quickly fail. There are various ways to resuscitate such containers, but this is quite problematic, and they are not restored completely and not for long. Lithium batteries have no memory effect, but they do not withstand extreme temperatures well. But such batteries are more durable and much lighter than their counterparts. The cost of owning a lithium-ion battery will be the higher cost of the screwdriver.

What should be the torque in a screwdriver? Some clarification is needed here. This refers to the tightening torque of the screwdriver, or rather the torque. For car enthusiasts, the expression “torque” is probably familiar. In order not to overwhelm you with definitions, I’ll simply say that the tightening torque is the maximum constant load on a screwdriver at which the device can continue screwing at a constant speed. The higher the torque, the longer and thicker the screws you can “drive” into walls and other obstacles. Torque is measured in Newtons per meter and is abbreviated as Nm. It is advisable not to buy screwdrivers with a torque below 10-12 Nm.

Screwdriver, what rotation speed should I choose? Here you must determine for yourself. If you want to use the device only for tightening screws, then this is one thing, but if there is a desire or need to also drill something inadvertently, then this device should have completely different characteristics. When talking about characteristics, we will mean the rotation speed of the rotor. For standard screwdrivers it is about 750 rpm. There are also two-speed models, which can be more expensive, but here you already get two speed ranges. For example 750 and 1200 rpm. Is second speed so important for a screwdriver? It’s hard to say, because the work will be done in both cases. With small volumes of screw driving, you won’t feel this at all, but the screwdriver as a drill has already appeared on the horizon. But here again, the speed of a full-featured drill averages 2400 rpm. If your screwdriver is capable of this, then good. The opposite situation is when they want to get a screwdriver from a drill. This will not exactly be an equal exchange, since the drill does not have a friction clutch. A friction clutch is a device that is adjusted to operate at a certain torque value. If you tighten small screws, then set the triggering moment less. Otherwise, at a high moment, the screwdriver will drive the screw so deeply that this may cause the wall, board and other parts into which this screw was screwed to be rejected. By default, a drill does not have a friction clutch.

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Is it worth buying a screwdriver with a hammer drill function? A hammer drill is a function of a drill and it is used to drill persistent surfaces such as concrete, brick, etc. If you want your screwdriver to work as well as a good drill, then feel free to purchase a model with such a “bells and whistles”. Otherwise, this is a redundant function and you shouldn’t overpay for it. Be sure to read the article Why concrete won't drill? Drills burn and break.

Screwdriver, whose to choose? A more precisely posed question sounds like which screwdriver manufacturer to choose. In this situation, the choice is up to you. We discussed all of the above selection factors. You just have to proceed from the parameters of convenience, price and personal sympathy. We will not list well-known brands and tell you about their advantages and disadvantages. You work with the tool. Look. Is it comfortable to hold in your hand, will it be heavy when performing long-term work, etc. We are sure you will get what you need!

Screwdriver power

In most screwdriver operating instructions, such an indicator as power is not indicated. However, for those who choose a tool, it is perhaps the most important. But it is not indicated because the concept is, one might say, a composite one. So, what determines the power of a screwdriver? This is, first of all, battery power and torque. In order to evaluate the power of a screwdriver as a whole, you need to take all these indicators into account.

Torque, that is, the rotating force that the tool develops, determines the length and diameter of the screw that the screwdriver can tighten. The higher it is, the greater the power of the screwdriver. The torque rating varies depending on the material being drilled. The technical data sheet of the tool usually indicates the size of the maximum possible drilling diameter for various materials. In addition, a distinction is made between hard torque (starting power) and working torque, that is, constant. The hard moment is always higher than the constant one. It should also be noted that the torque of modern screwdrivers is an adjustable value; technical data sheets, again, indicate how many installations the screwdriver has and the maximum possible torque. The maximum torque ranges from approximately 10 to 60 newton meters (Nm). It would be useful to note that, all other things being equal, the power of a screwdriver increases significantly if it has a function of operating in pulse mode (jerks). Power is increased by periodically applying hard torque.

You should not strive to acquire the most powerful tool. If you use too much power, you will drive the screws in too hard and the head will be deeper than the surface, which will spoil the appearance and make it difficult to remove the screws if necessary.

Let's summarize. Before choosing which screwdriver power is right for you, you should decide for what purpose the tool will be used. For rare use in a home workshop, a simple low-power tool with a voltage of 12V, a capacity of 1.2Ah and a maximum torque of 10Nm is suitable. This tool can be used to assemble furniture and screw in small self-tapping screws for fastening home furnishings (curtains, paintings, etc.). The highest power is achieved with 36 V, 3 Ah and 60 Nm. Such screwdrivers are considered professional, working with them requires certain skills, and their price is quite high. In any case, before purchasing a screwdriver, you should carefully study the technical data sheet and compare all the given values in order to understand what final power is available to the tool you have chosen.

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vashinstrument.ru

What voltage is better to choose a cordless screwdriver, difference in voltage

When choosing the right screwdriver for a particular task, you should pay attention to various characteristics. Among them, the most important are not only the power of the device and the capacity of its battery, but also the battery voltage, and even the torque value.

When carrying out construction and repair work, a screwdriver is an indispensable tool that simplifies the tightening of various types of fasteners, and sometimes even drilling holes. And, despite the fact that there are two versions of this device - mains and battery-powered, more often the latter option is chosen to perform household tasks. At the same time, attention is paid to the parameters of the power tool itself and to such characteristics as the voltage in the screwdriver, its power, torque and battery capacity. Each of these indicators is important for evaluating and choosing the correct device. Whereas it’s not worth buying based on suitable power or voltage alone.

Basic parameters of the battery and the tool itself

The main parameter that characterizes the operation of a screwdriver is the battery voltage, which, in turn, determines the electric motor power and torque. For household models, the difference in voltage between screwdrivers is small - on average, it is in the range of 10.8–14.4 V. More productive options intended for constant use can be equipped with 24–36 volt batteries.

The battery voltage of a screwdriver also depends on the type of battery - you can answer what the difference is by knowing what metals were used to make it. For nickel-cadmium batteries, large in size with a similar capacity, the value of the indicator is a multiple of 1.2 V (this is the voltage of one element that makes up the battery pack), for lithium-ion batteries - 3.6 V.

Other equally important characteristics include:

the power of the screwdriver, which can also be used to determine the speed of tightening screws and self-tapping screws. To carry out repairs on your own, models with a performance of 500–700 W are sufficient. A professional repairman will need more powerful equipment - 800–850 W;
the number of revolutions of the rotating part of the device per unit time. This parameter determines whether the screwdriver can perform the task assigned to it - for example, tighten the required type of fastener. So, for a bolt, self-tapping screw and screw, 500 rpm is enough, for drilling you will need 1200 rpm;
torque, the value of which can be one of the main answers to the question of what the voltage of the screwdriver battery affects. Using this characteristic, you can determine both the diameter and the length of the screw or self-tapping screw being screwed. Large fasteners, as well as drilling deep and wide holes and hard materials, require significant torque. The maximum value of the indicator is 10–60 Nm.

There are two types of torque for screwdrivers - starting (larger in magnitude and required to put the device into operation) and constant, that is, working. The parameter value for modern equipment models can be adjusted - you can find out how many modes can be selected for a particular device in the documentation available for it. Moreover, tools with a pulse mode of operation (turning on the rotating part in jerks) have more screwing capabilities - allowing them to periodically increase the torque, they can screw in a larger screw.

The output torque value of electric motors is not constant and depends, first of all, on the speed of the motor; the higher the speed, the lower the torque on the shaft.

In addition to the voltage of the screwdriver and its power, the battery capacity should also be assessed. The characteristic is measured in ampere-hours or milliamp-hours. The higher the indicator, the longer the screwdriver can work without recharging.

The average battery capacity of a household model is 1300 mAh, which is enough for 2–3 hours of operation. Professional equipment requires more time to complete the work - and a master who uses a screwdriver throughout the whole working day should purchase a model with 1.5–2.0 Ah batteries.

Features of choice

When choosing power, you should take into account not only what power of the screwdriver is indicated in the information from the manufacturer. Due to too much productivity, the device may tighten the screws too tightly, pressing their heads into the surface. As a result, the appearance of the coating deteriorates, and the fasteners, if necessary, are almost impossible to unscrew.

When choosing which voltage is best for a screwdriver, you should take into account that voltage is the main parameter of the device. For example, the motor power of the Makita DDF343SHE screwdriver is 700 W, with a voltage of 14.4 V and a battery capacity of 1300 mAh and a torque of 36 Nm. Whereas the other model Hammer ACD182 has a weaker engine (22 Nm) and a less capacious battery (1200 mAh) - and it seems that this device is about 40% weaker. However, due to the 18 V voltage, the Hummer is able to tighten more fasteners without recharging, even being inferior to its competitor in terms of battery capacity.

You can understand why a screwdriver that seems less productive at first glance is inferior to a more powerful one by doing a little calculation:

the amount of energy stored by the first model is 1.2 x 1.8 = 21.6 Wh;
the second indicator is only 1.3 x 14.4 = 18.72 Wh, i.e. 15.4% less.

When choosing a screwdriver, it is advisable to take into account the presence of a spare battery included with it. Some models even have 2 additional batteries. On the one hand, such equipment will cost more (especially since the cost of the battery is up to 80% of the price of the equipment), but it will be much more convenient to work with it. At the same time, an additional battery is not needed to perform household tasks - the time of work performed with its help rarely exceeds 1–2 hours. While in the process of constant use of a screwdriver (for example, for repair work or furniture assembly), the second battery allows you to not interrupt the work for longer than a few minutes. The discharged battery is charged, and a spare battery is installed in the device.

If there is no need for long-term work, which may require a screwdriver, it is not recommended to buy a model with additional batteries, not only because of its increased cost. It’s just that the service life of such a battery is short, and after a couple of years the user will have to buy a new part without using up even half of the life of the old one.

Summarizing

To summarize the article, it is worth noting that the battery power of a screwdriver, although it is an important parameter when choosing a suitable model, the voltage and capacity indicators are much more important. And most often it is worth paying attention to torque only if it will be used to not only screw in, but also drill. You should also know that the maximum power of a cordless screwdriver of all commercially available models is a device with a voltage of 36 V, a torque of 60 Nm and a capacity of 3000 mAh. Such equipment is quite difficult and not very convenient to use without professional experience. This means that you should opt for less productive options produced by well-known and reliable brands such as Bosch, Hitachi, Makita, AEG, Dewalt and Metabo.

Video: What a screwdriver should be like. Power

Video: How to choose a screwdriver

Video: Which screwdriver to choose? Let's compare DeWALT vs BOSСH vs MAKITA!

sdelalremont.ru

Screwdriver current, measurement.

The topic of powering a cordless screwdriver from a 220 V network has already been partially discussed on this site. It was talked about how to select a power supply for a specific model of cordless screwdriver, and tests for tightening screws were shown. No measurements were provided of the current consumed by the screwdriver in various operating modes. This will be discussed further.

If you have a screwdriver and you mainly use it indoors, then I think you will find this article interesting and useful. Here we will talk about converting a 12 volt screwdriver with a ni-cd battery.

It would be a good idea to power a screwdriver for your home from an outlet. That's what we'll do today.

First, let's start with what the problem actually is. A screwdriver is quite a powerful device. Under load, even a weak screwdriver can consume up to 200 W of power. Batteries cope with this calmly, but in order to record from an outlet you need a power supply that will turn 220V alternating voltage into the constant voltage we need. Power supplies are mainly 12 or 24 V. Thus, it only makes sense to remake a 12-volt screwdriver.

The author, for example, just had one dead 12 V nickel battery left. That’s what we’ll mock today.

If we go to our favorite aliexpress, we will see that 12 V power supplies with decent power, measured in Chinese watts by the way, are very, very inexpensive. The price is a little cheaper than a good Chinese screwdriver.

A logical question arises: is there any point in redoing anything at all? So aliexpress will not help us in solving this problem. Therefore, I want to offer you another option that is several times more profitable.

Computer power supplies are pretty powerful guys. Also, finding such a power supply will not be difficult. You probably have something like this lying around at home, unused. And if not, then you can go to any computer repair shop and buy a used power supply for a couple of hundred rubles, say, 500 W.

Let it be wrinkled, dirty, covered in dust, but the main thing is that it works. There is usually a sticker on one of the walls containing detailed information on the power lines. On this block we can see the following characteristics: 25 A per 12 V line, and this is no less than 300 W of power.

Enough for a screwdriver. Such a power supply is of course quite large, but at the same time it is much cheaper even than Chinese units with lower power.

Let's start the remodeling.
The first step is to disassemble the original battery and remove all the batteries from it. Our goal is also to preserve the terminal holder and the terminals themselves, so we carefully disassemble everything and free the terminals from the batteries. The author plans to make the battery pack removable so that it can work both from batteries and from the mains. That is, you get such a universal plug with terminals and wires.

You will need to solder a wire with a cross-section of, say, 3 mm 2 to these terminals. In theory, this should be enough to ensure that the energy does not dissipate into heat, even over a wire length of about 2 m. We take a soldering iron and, having previously prepared the wires (by stripping them of insulation and irradiating them), solder them to the terminals.

I don’t know how it will work with your screwdriver; personally, the author managed to bend the terminal ears directly into the plastic and it turned out very reliably.

Now we remember that the negative wire will be, say, blue and insert the terminals according to the plus and minus symbols on the battery case.

Supporting it from below, for example, with a screwdriver, we drill a hole through with a drill with a diameter of 3 mm. Then we remove the chamfer with a large drill. Moreover, we remove it so that the m3 screw with the countersunk head does not stick out.

Well, all that remains is to tighten the nut. This option with a screw is many times better than any other fastening.

Also, it is highly advisable to place a 16 or 25 V capacitor with a capacity of about 10,000 μF in parallel with the terminals. You can buy a capacitor at any radio market, in any radio goods store, or you can also pull it out of a dead computer unit. There is a way to get such a capacitor for free. Most likely they will give it to you for free at any computer repair service. They throw them out anyway. You just have to ask. So take action.

The capacitor will serve as an energy buffer for inrush currents. This is necessary in order to reduce the load on the power supply. If this is not done, with a high degree of probability it (the power supply) will go into protection. We take it and solder it. In this case, the author recommends gluing the nut with superglue. Otherwise you simply won’t be able to tighten it.

Next, we remove the wire from the housing. At this stage it is necessary to fix it somehow. This is necessary so that it does not create a load on the terminals. Fixation can be done, for example, by wrapping the cord at the required length with several layers of electrical tape.
Well, we’re actually putting everything back together.

Well, it's ready. The result is a plug battery with wires to power the screwdriver from the power supply.
Now it's time to test the homemade product. First, just for fun, let's try to power the screwdriver from a Chinese power supply with 10 Chinese amps. The author has one just like this for experiments.

We monitor the operation indicator (blue LED on the power supply housing). When the screwdriver starts, the block goes into protection.

He is unable to cope with his task. So let's go back to the computer power supply. This example has two 12V lines. One is 25A on the yellow wire, and the second is also 25A on the yellow-black wire. Actually, we take one wire and two grounds and connect them in parallel.
If you only have one 12V line, then just use 2 yellow wires and 2 black ones. By the way, the author read on the forum that for people on an old two-hundred-watt power supply with one 12 V line, the screwdriver works great.

The author decided to make everything beautiful. Therefore, the wire will be disconnectable. The XT60 power connector will come to the rescue; it costs about 25 rubles on Aliexpress.

This is not necessary, it will just be more convenient.
In order to start the power supply from a computer without a computer, you need to close the PS-ON contact to ground (GND). Accordingly, the green wire to black. This can be done with a jumper made of an ordinary paper clip. That's it, the block starts.

All excess wires can be cut off, but the author will not do this, since he may still need the block for other purposes.

Finally, I began to implement my long-standing idea, namely, to provide power for the screwdriver from a 220-volt network. Undoubtedly, some of you also have a screwdriver with a worn-out, unusable battery that no longer takes a charge. I had two copies at my disposal.

The first (black) operating voltage is 18 Volts. This is what I initially wanted to power from the network, because... It fits comfortably in the hand and is quite powerful. But the button is missing. Perhaps in the future I will cut off the handle and make it into something like a drill. The second copy is designed for 12 Volts. Served for quite a long time. Of course, you can purchase a new battery or, in extreme cases, replace the banks. But still, you want to always have a ready-made tool at hand, especially since an electric drill is not always convenient to use because she's heavy. A power transformer will help us realize this idea.

A step-down transformer TS-250-36 was used. "250" is its rated power, and the number 36 means that the output voltage will be 36 V. It has an O-shaped magnetic circuit. Its windings are arranged in such a way that half of the primary is wound on the left, the second half on the right side. The secondary winding, which is located on top of the primary, is wound in a similar way.
It is not difficult to distinguish the windings from each other in a step-down transformer, because the secondary one is made of a thicker wire, and the one to which mains voltage is supplied is made of a thinner wire. This is due to the fact that a smaller current flows through it.

The windings have a symmetrical arrangement and two halves of 18 volts are connected by wire (the connection point is clearly visible in the bottom photo). I'll use one half.

But before you rewind the transformer, you need to take measurements. I urge you to be careful when working with current, do not touch live parts, and always check that the measurement limit on the multimeter is set correctly.

On the right, the voltage is measured on half of the secondary winding. As you can see, the voltage slightly exceeds the rated values, because there is no load connected here.

So I separated one half and now we begin to disassemble the transformer. There was a large amount of paraffin between the layers of paper.

The secondary winding in my case is wound in two layers, separated by a layer of paper. To reduce the secondary voltage from 18 volts, almost half of the turns had to be removed.

When determining the required voltage, you need to take into account that after the transformer there will be a diode bridge, which will reduce the voltage by about a couple of volts. But adding a smoothing capacitor will cause the voltage to increase by about 1.4 times. Those. in the absence of load, the rectified voltage on the capacitor will be equal to the amplitude value.

As the secondary unwinds, we take measurements. Soon, I settled on a value of 11.2 Volts, because... I was afraid of drawdown when connecting the load.

Once the transformer is prepared (although some may use a ready-made one with the required parameters), now it's time to get acquainted with the circuit.

A diode bridge (VDS) must be soldered to the output of the transformer to convert the alternating current into a pulsating direct current.
The diode bridge can be assembled from separate diodes or used ready-made. When selecting it, you should take into account how many amperes your screwdriver consumes (choose the bridge with a margin).

We solder the wires from the secondary winding to the terminals of the diode bridge, where the letters AC (alternating current) are.

Well, after the bridge you need to solder a capacitor to smooth out the ripples. Its voltage must exceed the supply voltage of the screwdriver at least twice. And the capacitance is from 470 µF to 2200 µF.

If desired, a switch and fuse can be added to the circuit in front of the transformer.

So, after connecting the circuit, I took measurements. The idle voltage at the output of the power supply (when no load is connected) is 15 volts. When starting the screwdriver, it drops to 11.5 volts, which is normal, so it’s okay. A fully charged new battery produced 13 volts.

This is what the instrument looks like from the inside. Here you can find the limit parameters of the button, and you can also notice that the motor is controlled by a powerful field-effect transistor.

To make it easier to connect to the power supply, I disassembled the battery. We will need contacts from him.
This part needs to be tinned. I did my soldering using rosin, but in some cases you may need flux for soldering aluminum.

Of course, when soldering wires from the power supply, do not forget about the polarity; it is usually indicated on the battery case.
The compartment became very light. The wire was sealed with hot glue.

Tests showed that the screwdriver coped with the tasks when operating from the power supply.

This article has a video that shows in detail the process of creating a power supply, rewinding the transformer, connecting and testing.

List of radioelements

Designation	Type	Denomination	Quantity	Note	My notepad
T	A step-down transformer	Select by voltage	1		To notepad
VDS	Diode rectifier assembly	PBL405	1	Better more powerful	To notepad
WITH	Electrolytic capacitor	470...2200 µF	1	Not less than 50V

Let's look at the power components separately:
- Battery voltage. It determines the engine power and torque, as well as the operating time of the screwdriver. The average power of household screwdrivers is 10.8-14.4 volts (V). However, there are models with batteries up to 36 volts.
- In addition to voltage, it is worth evaluating its capacity, which determines the operating time and is measured in ampere hours. The average battery capacity of a screwdriver is 1.2-1.5 Ah.
- Torque, that is, the rotating force that the tool develops, determines the length and diameter of the screw that the screwdriver can tighten. The higher it is, the more screwdriver power. The torque rating varies depending on the material being drilled. The technical data sheet of the tool usually indicates the size of the maximum possible drilling diameter for various materials. In addition, a distinction is made between hard torque (starting power) and working torque, that is, constant. The hard moment is always higher than the constant one. It should also be noted that the torque of modern screwdrivers is an adjustable value; technical data sheets, again, indicate how many installations the screwdriver has and the maximum possible torque. The maximum torque ranges from approximately 10 to 60 newton meters (Nm). It would be useful to note that, all other things being equal, the power of a screwdriver increases significantly if it has a function of operating in pulse mode (jerks). Power is increased by periodically applying hard torque.

Let's summarize. Before you choose which one screwdriver power suits you, you should decide for what purpose the tool will be used. For rare use in a home workshop, a simple low-power tool with a voltage of 12V, a capacity of 1.2Ah and a maximum torque of 10Nm is suitable. This tool can be used to assemble furniture and screw in small self-tapping screws for fastening home furnishings (curtains, paintings, etc.). The highest power is achieved with 36 V, 3 Ah and 60 Nm. Such screwdrivers are considered professional, working with them requires certain skills, and their price is quite high. In any case, before purchasing a screwdriver, you should carefully study the technical data sheet and compare all the given values in order to understand what final power is available to the tool you have chosen.

I have an old Black & Decker Firestorm screwdriver with a long dead battery. A new battery in our area costs about 40-50 dollars, and a new screwdriver costs 60-70. It creates a strong feeling that you are being deceived somewhere. Therefore, it was decided to remake the old one with an estimate of $30.

First you need to determine the operating current of the screwdriver. To do this, take a thicker board and a longer screw. We set the gearbox to maximum torque and screw it in, simultaneously measuring the current consumption. My Firestorm showed 15A while it was turning and 17A -20A in the motor short circuit mode. I measured it with a regular multimeter at the 20A limit.

We go online and look for a Li-Po battery of suitable size, with an operating current of 20A and at a reasonable price. This one was found. The main thing you need to pay attention to when choosing, in addition to the operating voltage and capacitance, is the supplied current. The battery life directly depends on it. Otherwise, the battery will swell.

UPD: hint from the comments: Don't chase capacity

I somehow twisted the nuts with a 4S lithium at 1300mah for 2 days in a row and was never able to seat it.

For the battery that I chose, the discharge current is 35C or in normal language 1500mA X 35 = 52500mA (52.5A). After receiving the parcel, the battery was tested on the iMax-B6, the charge current was set to 1A - the capacity corresponds to the declared one.

The next stage is to find a suitable protection/charge board with a return current of 20A. On the forums, it is categorically not recommended to connect without it - the battery quickly degrades from a deep and uneven discharge or may explode when trying to charge a battery that is set to zero. The board I needed was found on eBay (Aliexpress turned out to be expensive).

We connect the battery according to the following diagram. For this we need connectors - and .

After which you should get something like this

The screwdriver has come to life and makes my “toad” happy. For charging I used the standard Black & Decker charger from Ni-Ca at 14.5v, 200mA. It charges slowly but surely.

UPD: At the end of the charging process, the voltage on the battery was 12.5v or 12.5v / 3 = 4.17v per cell (according to the standard it should be 12.6v or 4.20v per cell).
In standby mode, the protection/charge board consumes 3 microamps per cell (measured with a multimeter on a 200mA scale).

UPD: As correctly noted in the comments, never leave the battery while charging. even apple products sometimes explode