How to convert a 12 volt electric screwdriver battery

Instructions for charging a lithium battery

Modern screwdrivers are equipped with lithium-ion (Li-ion) batteries, so we will charge devices of this type. If you don’t have a regular battery charger (battery charger) handy, there are several ways to solve the problem:

• Use a car charger;
• use a car battery;
• charge the battery with the laptop power supply;
• Use a specialized charger for lithium batteries;
• Use a laboratory power supply.

Since lithium batteries are capricious and can even be dangerous if not properly charged, let’s break down each option in more detail.

From a car charger

The device for charging car lead-acid batteries at 12 V voltage every motorist has. But a charger is not a charger. We need at least one that allows you to manually adjust the charging current. Though the ideal variant will be charger with stabilization of current, and it is even better with stabilization of current and voltage.

If we have a machine, it’s easy. Set the final charging voltage. It is easy to calculate with this formula: The final charging voltage of one lithium battery pack (4.2 V) multiplied by the number of batteries in the battery. For example, a 12 volt lithium battery has 3 batteries. Therefore, it is necessary to set the voltage on the charger to 12.6 В. Then turn the charging current regulator to zero, connect the battery of the electric screwdriver, observing the polarity (positive battery to positive terminal, negative. to negative), turn on the charger and set the charging current no higher than 25% of the battery capacity of the electric screwdriver. The capacity of the battery is usually marked on the battery case.

Lithium batteries can be charged with current equal to their capacity, but this mode causes rapid degradation of the cells. It is better to use it when “there is no time, but the edge is needed”.

All we have to do is wait. When the battery is charged, the charger will automatically stop the process.

If we don’t have stabilized current and voltage, we have to constantly monitor the charging current, which will change as we charge, and the voltage. If the charger has its own voltmeter and ammeter, then use them. If not, you will have to add meters to the charging circuit. It looks something like this:

Lithium batteries do not tolerate overcharging. An overcharged lithium cell will catch fire or even explode. Therefore, carefully monitor the battery voltage.

From a car battery

This method is only appropriate for cordless screwdrivers that have 12 volt battery chargers.

But you must not connect the battery of an electric screwdriver directly to a vehicle battery. You must limit the charging current. This is not difficult to do with a tweaking wire resistor of at least 10 watts or car lamps connected in parallel. How many lamps we need. choose experimentally. They must provide a charging current in the range of 10. 50% of their capacity. Too much charging current can cause the lithium battery to explode, too little will significantly increase the charging current.

Add to our circuit a meter, a voltmeter and an ammeter. above), and start charging, constantly monitoring the voltage. Once it reaches the correct level (4.2 V multiplied by the number of batteries in the electric screwdriver battery), stop charging.

You can only charge a 12-volt electric screwdriver with a fully charged battery. If it is discharged and the voltage on its terminals is below 12 V, the electric screwdriver will not charge.

With a power supply from a laptop computer

This method is great for charging any electric screwdriver, whether it is a twelve- or eighteen-volt cordless screwdriver You only need a 19 volt laptop power adapter for this.

The charging algorithm is the same as that for charging from a car battery. We limit current with ballast resistor or car lamps, add measuring instruments to the circuit, connect the battery of an electric screwdriver and charge it, constantly monitoring the voltage.

With a special charger

The most convenient, but not the cheapest option is a universal charger. For example, what is shown below, is about 2 500. And it’s not the most expensive option.

Universal automatic battery charger

But this device knows how to charge almost all types of batteries and accumulators at any voltage. We only need to tell the device the type of battery and its capacity. All the current information is shown on the display, including the charging time, current degree of charge, how much energy the battery has received, etc. There is a built-in balancer for balancing individual batteries, an automatic discharging device, a battery capacity meter, and much more.

So, we only need to charge an electric screwdriver. We go to the store and look at. Here’s what we need. Relatively cheap (from 250 to 350 depending on the output voltage) and smart. The main thing. buy one that is designed for the voltage we need. They all look the same, but differ in output voltage. 12.6 В, 16.8V, 21V, 25V and a current of 1A, 2A. The one in the picture is a 12 amp socket.6 volts and provides 2 amps of current.

Tell the salesperson what kind of battery we have (voltage and capacity) or what voltage and current we need the charger for. We pay for it, take the warranty card, charger, and go home to try it. We don’t have that socket? No problem. It comes with the charger:

If it’s not in the kit, it’s not hard to find separately in the same store. Insert the socket into the battery. We are soldering, observing polarity: internal pin. “plus”, external pin. “minus” (this information is put on the charger case). Connect the charger and smoke. While charging, on the charger glows a red light. Once the process is complete, the red peephole will change to green and the charging will stop. Disconnect, go screw the screws.

Important! Although this device looks like an ordinary adapter, in fact, it is an automatic charger for lithium batteries. You can not use it as a power supply.

By the way you can order such a charger for lithium batteries from aliexpress:

Screwdrivers with 12 volt batteries need a 12 volt battery charger.6 volts, sellers may refer to it as 3S (from the name of the battery assembly. 3 in series).

For screwdrivers with 14.A 4 volt battery needs a 16 volt charger.8 volt, the sellers may refer to it as 4S (4 banks connected in series).

With a lab power supply

Here the process is no different from working with a car charger. Set the desired current, if the power supply allows, the final voltage, and charge. If you can’t set the final voltage, then watch the current and the voltage. Once it reaches the set value, the battery is disconnected.

Convenience of such variant is that it allows to charge screwdrivers with any voltage of the battery, as practically all laboratory PSU can provide 25 V. For example, the one shown in the photo produces a voltage of up to 30 V at a current of up to 5 A.

Just as a side note. Buying a labtop power supply to charge an electric screwdriver makes no sense. It is easier to ask a radio technician you know, who probably has a similar device. Or maybe you have one.

Sometimes you can recharge via USB

There are screwdrivers equipped with a USB port. Example. Electric screwdriver Xiaomi Akku Ankuo.

If you have one of these, no problem. According to the manufacturer, this tool can be charged even from the USB-port of a computer and laptop! But he (the manufacturer) modestly glosses over the time it takes to charge your laptop with this kind of charger. A week? Two? So it is better to use a 5-volt AC adapter which can supply at least 2-3A of current. True, there is another problem: you will have to find in the store or make your own USB/USB cable.

Important! There is a lot of information on how to convert the usual screwdriver for USB charging. It is suggested to simply cut the appropriate socket into the electric screwdriver and solder it to the battery. This is nonsense, which wrote one literate, and the rest of his copied.

How to convert a 12 or 18 volt cordless electric screwdriver into a corded tool with your own hands

The cordless electric screwdriver was designed primarily for mobility. It is much more convenient to work with the tool without thinking about whether the wire is long enough, whether it gets snagged, etc. д.

But without batteries, such a handy tool, like an electric screwdriver, becomes a simple piece of iron, although it is fully functional. Battery life is about 3 years, and it is often impossible to find complete or similar batteries on sale. For example, the manufacturer has stopped producing this model, and other batteries are not suitable for various parameters.

It can be very regrettable to throw away a tool for which you have paid money at one time, sometimes a pretty penny. Besides, the cost of batteries is often up to 80% of the price of an electric screwdriver, and it would make more sense to buy a new tool. As a rule, old tools are sent to a distant shelf and lie there uselessly. But there is a way to get it back to work. to convert it to power from a 220 volt electric network.

Remaking an electric screwdriver with their own hands

There are enough handymen in the household, there are many ways to remake an electric screwdriver for mains power. It is enough to provide the required voltage for the electric drive of the device.

Cordless electric screwdriver disassembled

In some cases, for remaking, it is sufficient to use the charger from the kit, it is available, t.к. is supplied with the electric screwdriver. To remake such a design is simple enough, just disassemble the electric screwdriver, connect the output pins on the charger to the drive wires. The voltage produced by the charger after conversion, corresponds to the specifications of the drive, for the safety of the electrical part is not worth worrying about. It is also worth noting as a plus that there is no need to disassemble the entire device, because it is not necessary to use it.к. It is necessary to connect only the wires designated for use. A significant disadvantage is the size of the battery charger, to constantly move it when working is not convenient and delivers discomfort.

Power from the electric screwdriver can be achieved by several types of units. The housing accommodates some of them, the rest are outside.

There are plenty of ways to convert a cordless electric screwdriver, all have pros and cons.

• In the case of the old battery, a place for the finished PSU is organized. Change is not difficult, interference in the electrical circuit is not required, just accurately perform the work to achieve a perfect look. The disadvantages are the time required to find a block with the appropriate voltage and dimensions. Also small devices are usually heated when closed, it is necessary to provide the device with ventilation by making holes in the case.
• Installation of a homemade power source is a more complex solution, requires to find the necessary radio components and understand the circuit. The pluses of this way of remaking are low financial costs, no losses when using low voltage cable, no changes in the appearance of the device.
• An external PSU can be used when working in one place, because the mobility and compactness of the device is lost. There is also the expense of finding a suitable voltage to the electric drive of an electric screwdriver.
• The most common external device is a computer power supply. The advantages are that it is easy to find at salvage yards for a reasonable price, there are no complicated processes of rework. However, cumbersome construction will not be to everyone’s liking.

How to Connect an Electric Screwdriver to a Car Battery

How you can do it? Isn’t it dangerous for the electric screwdriver?

Т.к. the work of an electric screwdriver is connected with jolts of voltage at switching on and off, the car battery is suited as the best, because the normal mode of operation of the latter is associated exactly with the discharge-discharge mode. As for the damage to the device itself (screwdriver). There is no reason to be afraid. it consumes as much as it needs. However, for the good work of an electric screwdriver from a car battery its working voltage must be in the region of 12V.

The electric screwdriver can be connected to a battery by means of a flexible copper cable to the plus/minus pole of the device and the battery respectively.

Connect the screwdriver to the car battery can be if they match on the voltage, namely, the screwdriver will be specified marking 12 V (such on sale enough!), in which case you can simply connect it as a temporary cable and work without fear.

But a large number of wrenches have a higher voltage of both 14V and 18V. in this case, for stable and high-quality work of the wrenchinder it is necessary to use a rectifier with regulation of voltage increase, otherwise the wrenchinder will be crushed because of the weak power, and the battery amperage will heat it. which may lead to damage to the electric device.

As a rule we deal more often with screwdrivers for 12-14 volts. This is the optimum voltage and is therefore quite suitable for an electric screwdriver connected to a car battery. The important thing here is not to reverse the polarity of the minus plus. Even if your electric screwdriver is 18 volts, no problem. It can be plugged in too, just a little bit less power. But it is not terrible, it is an electric screwdriver, not a negotiable drill. Its work such an electric screwdriver will do fine.

If the screwdriver is designed for 12 volts then of course you can connect it to a car battery and not only.Even a battery from an uninterruptible power supply will work. It’s also rated at 12 volts.The main thing is not to mix up the plus and minus terminals of the screwdriver.As a protection against improper use you can try to connect a diode in the gap of one wire.It just theoretically should help against improper switching.

I threw the calculation in excel (file attached) on the issue of voltage drop depending on the cross section of the wire and load is good if some educated person looks and confirms or says to fix it, would screwdrivers connect to car batteries good teaching material. Thanks to Alexander IV for the idea. The wire from the battery to the screwdriver I counted as 2 long (to it from him) is correct, no?Later added by the author:

I am interested in the reason for this manipulation?? cordless tool is more expensive and we pay extra for convenience of not having a wire. Besides, you also need to service the battery.

1) money and unexplored creative engineering potential which wants to show. Used electric screwdriver without a battery with a dead battery can be bought for small money to just get as a gift, you can buy a new one from the same Makita without a battery cheaper. 2) the convenience of using an electric screwdriver, which has a bar at the bottom is also very relative phenomenon in the first place without battery electric screwdriver is lighter and more compact, and a small electric screwdriver 10.8 to which I started talking about even a pea, I’m not confused by the wire and I am ready to have a light tool on a wire. second, I have seen many times how installers in winter (in our Siberia.20-30) suffer with these cordless screwdrivers I do not know what their convenience is to run every 15 minutes to recharge the battery, I never understood why they do not solve this problem for themselves. 3) Regarding the fact that you need a car battery, as a motorist usually have a decent amount of accumulated them on which the winter will not be able to go, and throw out or give for 300 rubles as boilers sorry. Amps 10 or even 20 can easily fit in there, and it is a few days of work, if not a week.

I would rather think about the subject of connecting a power tool to a battery.

the idea is certainly interesting, but there are objective laws of physics and there are actually ready-made solutions. The laws of physics is that the battery does not hold much, and the usual powerful power tool consumes a pretty decent.

the ideal consumer of a corporation is a person who has absolutely no idea about the product’s construction and who follows the manufacturer’s instructions exactly when to replace consumables in good time and brand name. to get a power inverter, it has its own problems, but it is easy to buy for a good price and there are some problems with the number of full discharge cycles and it is important that a used car one will not fit for free, you will have to buy a new one for a good price. so it turns out that the question is whether you’re willing to pay a lot of money for a few hours of power tools on batteries. Again, there are ready-made solutions from manufacturers which are as they should be a bit more expensive. although I have a 800w inverter, the easiest Chinese one, it is quite capable of pulling a regular mains drill of appropriate power. Later: checked with this Chinese inverter 800w drill 650w grinder 350w jigsaw 450w for a bit they worked fine, so the problem of powering a corded tool from the battery is generally not, except that in the 60Ah automotive battery new fit where something 800w and it will lead to its complete discharge is undesirable.later added by the author:

By the way my question is why all manufacturers of battery tools these batteries are sold as a whole. and no one has the cartridges for them. I have to look for them at the radio market!

because the ideal corporate customer is someone who has no idea how the product works and follows all the manufacturer’s instructions to replace consumables in good time with genuine replacements.

Which power supply to choose

The first question that arises when converting cordless power tools to mains power is what to power the electric tool from. To select a power supply for an electric screwdriver, you must ask yourself the following initial data:

• supply voltage (depends on the power tool model, in most cases from 12 to 18 v)
• no-load current. 1.2 А;
• average current consumption (drilling in light materials, unscrewing screws, screwing screws into soft materials). 3.6 А;
• current consumption in maximum mode (drilling of solid materials, screwing in metal parts without torque limitation until the complete stop of the shaft). up to 12 A.

Also, the power supply must be able to withstand the short-term starting current of the electric motor, which can be 2.5 times of no-load current.

Screwdriver typePower supply voltage, VBattery typeMaximum torque, Nm

DEKO 12V DKCD12FU	12	Li-Ion	28
Bosch GSR 120-LI	12	Li-Ion	30
Megamaster 144Li	14,4	Li-Ion	20
Edon AD-18C	18	Li-Ion	28
DEKO 20V DKCD20FU	20	Li-Ion	42

By wattage

an electric screwdriver must produce a high torque, so it requires quite a lot of power (even with a relatively high efficiency), but not necessarily set to the maximum. To determine power requirements, consider the operating conditions in which the power tool is typically used. If an electric screwdriver is not used at maximum load, you can choose a power supply of 60-70 watts. If your power tool is to deliver everything it was designed for, you may need a power supply of 200 watts or more.

Type (pulse or transformer)

To operate an electric screwdriver it is desirable to have a stabilized power supply. The voltage of such a power supply under load practically does not drop. Accordingly, even with a heavy load, the power tool can deliver the greatest torque. Here too, pulse sources are beyond competition. Because a typical transformer voltage source even in medium voltage mode has a power loss of 10-15 watts. This power must be dissipated somehow, without overheating the regulating transistors. This would require a large and bulky heat sink. Such a power supply also includes a heavy transformer, powerful diodes on heat sinks, and a large smoothing capacitor. For 200 watts such a power supply will have no mobile dimensions and weight at all.

It is possible to buy a universal power supply. There are units that are specifically designed for powering screwdrivers. They do not differ much in principle, but the specialized sources have a voltage rating that matches the standard ratings of electric tools, and a current that is sufficient for operation in the most severe regimes.

Another option is to convert a switching power supply from a desktop computer. It can draw enough current to run an electric screwdriver, but the unit must be rebuilt for the right voltage. Such alterations of the power supply circuit requires a certain skill, and depends on the design of the power supply. Process descriptions for units based on different chips can be found on the World Wide Web.

For power tools powered by 18- or 20-volt batteries, you can use 19-volt power supplies from laptops. But it’s only good for 3 amps of current.It has a rating of 6A, so it may not be used at its highest setting. Either the self resetting fuse or thermal cutoff will blow, or the power supply will fail.

On the Internet you can find recommendations as a power supply to use the battery charger for an electric screwdriver. This idea is not a good one. The charger is designed to charge the battery with a relatively low current for a long time. Then a charged battery must release its energy quickly enough. The currents are high. So the charger from the electric tool will provide idle running of the electric screwdriver at best.

But stabilization is not always necessary. because the voltage of regular battery, especially not a new one, also drops substantially under the load. Therefore if you don’t need the stabilizer, you can pay attention to transformer power supplies. Let them lose in weight and dimensions to the pulsers at these capacities, but the traditional sources are simpler, more reliable and more maintainable. Besides it can be made by yourself picking up the suitable transformer. And if you intend to work only in stationary conditions, then the mobility of the device is of no importance.

The process of dismantling a battery case

The housing can be assembled with screws, locking mechanisms and glue. In the latter case, converting your electric screwdriver to lithium batteries will become much more complicated. The glued case should be carefully disassembled at the butt joints. They must be smashed using a mallet with a soft plastic head. Do not damage parts of the box, otherwise it will be extremely problematic to assemble it back, as well as working with tools. Self-tapping screws and latches are easy to pull apart.

From the disassembled box you need to remove all the contents. A contact plate (on some models it is a complete terminal assembly) will be needed for later reassembly. Use it to make a connection to the charger, etc.д.

Methods of connecting elements of the battery

The energy storage unit is assembled in one of three ways:

• Spot welding. If you do not have a welder at home, you can call in a specialist. This technique of connecting the elements into a block is the most preferred.
• Soldering. Every home must have a soldering iron. But when soldering all the manipulations must be done very quickly, because the solder cools down almost instantly. Avoid prolonged heating of the batteries. High temperatures will damage the cells. If you are not skilled in soldering, it is best to leave the work to a specialist.
• Cassettes. An alternative, but not the most reliable way. The contacts obtained in the process will have a significant transient resistance. So, you need to be prepared for the fact that at high currents it will quickly deteriorate. With the help of special cassettes, a quick connection of the batteries in the block is carried out.

The final stage

Now you need to combine all parts into one unit. precisely solder the wires to the assembled block and not to the protective board. All actions should be coordinated with the wiring diagram. Recommendations for assembly:

• Batteries are soldered to the wires with a cross section of 1.5 mm2. For other purposes you can use thinner contacts. 0.75 mm2 in cross section.
• Heat shrink tubing may be used to keep parts from coming in contact.
• Connect the assembly to the “plus” and “minus” outputs.
• Test soldered circuitry.

If everything works, the case can be assembled.

Hitachi Electric Screwdriver Conversion to Lithium Batteries

Some screwdriver owners want to recycle batteries from their condition to lithium battery cells.

There are a lot of articles on this subject and in the real article I would like to summarize the information on this topic.

First of all let’s look at the reasons for and against converting the cordless screwdriver to lithium batteries. And of course let’s look at the individual moments of the process of changing the batteries.

The first thing to think about is whether I need this alteration? It will be a frank “self-made” and in a number of all possible cases leads to the wear and tear of both the battery and the screwdriver. Therefore, it is necessary to consider what remains for and against this procedure. It may be that then some of you decide to renounce the conversion of Ni─Cd battery for the screwdriver to lithium cells.

• The energy density of the lithium─ion parts is considerably higher than that of the nickel─cadmium ones, which are used by default in electric screwdrivers. In other words, the lithium battery has less weight than the cadmium battery with the same capacity and output voltage;
• Charging of lithium battery parts is significantly faster than if Ni─Cd is passed. It will take about an hour to charge them safely;
• Lithium─ion batteries have no “memory effect. This means that they do not have to be completely discharged before you put them on charge.

Now for the drawbacks and difficulties of lithium batteries.

• Lithium battery cells can not be charged above 4.5 volts and discharged below 4.7 volts. In real criteria this interval is even narrower. If you go beyond these limits, the battery has the option of failing. Therefore, in addition to the lithium battery packs you will need to connect and install the charge-discharge controller in the screwdriver;
• The voltage of the 1st Li─Ion cell is 3.6─3.7 volts, for Ni─Cd and Ni─MH this value is 1.3.5 volt. In other words, there are tasks with the assembly of a battery for screwdrivers with a voltage rating of 12 volts. With three lithium batteries connected in series, it is possible to assemble the battery with a rating of 11.1 volts. Of 4 ─ 14.8, of 5 ─ 18.5 volts, etc.д. Than that and the charge-discharge voltage limits will also be different. In other words, there are problems of comparability of the converted battery with the screwdriver;
• As a rule, as lithium parts for conversion are used cans standard 18650. In terms of size they are different from the Ni─Cd and Ni─MH batteries. Today, you will need a place for the charge-discharge controller and wires. All of this will need to fit into a standard screwdriver battery case. Otherwise it will be very awkward to work;
• Battery charger for cadmium batteries may not be suitable for charging the battery after recharging. You will need to modify the charger or otherwise implement universal chargers;
• Lithium batteries become unusable at subzero temperatures. This is critical for those who use the screwdriver just outdoors;
• Lithium batteries cost more than cadmium batteries.

It is necessary to determine the number of parts in the battery, which ultimately decides the voltage. For three parts the ceiling will be 12.6, for four. 16.8 volts.

We are talking about converting the commonly available 14.4 volt batteries. It’s best to go with 4 cells, because during operation, the voltage will drop to 14.8 volts rather quickly.

A difference of a few volts will not affect your screwdriver’s performance.

Converting a Hitachi electric screwdriver to lithium

Already today, more lithium parts will give a huge capacity. And that means more working time of the screwdriver.

Lithium 18650 batteries

The rated voltage of the lithium parts is 3.6─3.7 volts and the capacity is almost always 2000─3000 mAh. If your battery case allows it, you can pack 8 instead of 4. Connect two of them in 4 parallel assemblies and then connect them one by one. Once completed you can increase the capacity of the battery. However, not many enclosures can hold 8 cans of 18650.

And the last preliminary step is the choice of the controller. In terms of its features, it must match the nominal voltage and discharge current. In other words, if you decided to assemble a 14.4 volt battery, then choose a controller with this voltage. The operating discharge current is usually chosen to be half as much as the maximum allowable current.

Above we have established that the maximum short term discharge current for lithium parts is 25─30 amperes. Means the charge-discharge controller can be rated at 12─15 amps. Then the protection will be triggered when the current increases up to 25─30 amperes. Don’t forget also about the dimensions of protection board. It will need to be placed in the screwdriver battery case together with the cells.

And then goes the process of assembling. At first you disassemble the battery case. If this model is 14.4 volts, then inside there will be 12 nickel cadmium batteries rated at 1.4 volts.

Converting a Hitachi 12 volt battery to lithium

After that it is necessary to solder the purchased elements into an assembly with the alternate connection. Then the controller is soldered to it according to its scheme. At the same time the balancing points are connected. There is a special connector on the board for their production, and often a wire and connector is supplied in the kit.

Once the battery is assembled, the plus and minus leads are soldered, and the entire structure is placed in the case. By and large, the process is complete at this point. Difficulties occur only with the charger.

However, for the most part, standard battery chargers for screwdrivers charge lithium cells freely. With all this, the charge of the jars goes through the controller, so something special does not happen with the cells themselves.

There are tips on the web for saving on the controller board. In other words, you buy the cheaper model, designed for the smallest current. And to keep it from limiting the screwdriver‘s work, it doesn’t discharge through a controller, but directly from the cans. And charging them, as it should be, goes through the controller.

Power Supply Options

Any electric screwdriver requires much less voltage than a regular socket. Therefore for charging you will need a special converter which outputs the necessary voltage. All power supplies are divided into two big groups: switching and transformer. Let’s consider each of them separately.

VOTO 12 Volt Lithium-ion Battery Cordless Screwdriver. Battery Replacement

Impulse

The principle of pulsed systems is that the voltage is first rectified and then converted to a special pulse signal. It is important to achieve a stable voltage. A transformer winding or resistors can help in this.

Switch mode power supplies are quite efficient and can be used in various conditions. Thus they have a high level of protection against short circuits and similar effects. But in terms of power, switching systems clearly lose out to transformer ones. Besides such units are very picky about the input voltage. If it is lower than a preset value, the cell may simply not work.

The transformer power supply

common power supplies that have proven reliable and efficient in many applications. Consists of a step-down transformer and rectifier, through which the undervoltage is passed. Rectifiers can be different, depending on the number of diodes used.

Such elements are simple to make, cheap and reliable. That’s why they are often preferred. They provide a stable voltage without interference with high maximum power. But there are a few disadvantages. The main drawback is that they are bulky, with much lower efficiency than pulsed sources. This fact requires a power adapter for an electric screwdriver that has more power than the tool needs. Since part of the power will go to side processes.

No matter what brand of power tool. Bosch, Interskol, Makita, Hitachi, etc. д., They all operate on the same principle. The energy is stored in the power element that gives it away when using an electric screwdriver. And the life of the battery depends on its type. Today there are 3 basic types, each of which has its own advantages and disadvantages.

Li-ion batteries

The most advanced solution today that is stable over a wide temperature range. And if the equipment is just lying around, the self-discharge per year does not exceed 20%, which is also very important. The main advantages are as follows:

• Fast charging without damage to equipment.
• Lithium-ion batteries have high capacity with low weight.
• No memory effect, so you can charge the battery as needed.
• The system provides high fire safety, also there is protection against overcharging.
• Greatest power capacity.
• In freezing temperatures the battery life is shortened.
• Li-ion batteries are much more expensive.
• Service life of 2 to 5 years.
• Each battery model requires its own charger.

By the way!

Ideal for frequent users.

Nickel-metal hydride batteries

In this variety, the quality of the alloys used is of primary importance, so each manufacturer has its own specific manufacturing technology. The option can be called the golden mean, as it does not contain toxic cadmium and has many advantages, among which the main ones are

• Affordable price.
• The memory effect is there, but not very big.
• Low weight and dimensions give high capacity.
• Good operating parameters in the permissible temperature range.
• Fairly high self-discharge rates.
• Battery capacity decreases after 200-300 recharging cycles.
• Heat dissipation during charging.
• Batteries do not function at temperatures above 40°C and below.10°C.

By the way!

Battery capacity drops and cannot be restored to its original state, so care must be taken to keep it charged.

Nickel-cadmium batteries

The least expensive option, which was most common a few decades ago. Simply put, these are traditional alkaline batteries that have these advantages:

• Low cost.
• Fast recharging process.
• Stable energy output at temperatures up to.20°C.
• Up to 100 charge-discharge cycles.
• Long shelf life.

There are disadvantages, too, which should be sorted out:

• High self-discharge during storage. After a long cycle without operation it is necessary to carry out the recovery process.
• Toxicity of cadmium.
• Batteries suffer irreversible damage if deeply discharged.

By the way!

If an electric screwdriver is used every day, you can also choose this solution. as the most budget-friendly.