How many amps are in the battery of an electric screwdriver

What is the ampere clock in the battery of an electric screwdriver

To screw in a screw is one of those tasks that appear out of nowhere, but with enviable consistency. To correct a warped closet door, to hang a mirror in the hallway, to attach a shelf in the bathroom. small household problems that need to be solved daily. Using a screwdriver to tighten the bolt, screw or self-tapping screw can be done, but is not always possible. Who tried it, knows: it is a thankless and long-lasting job, and the result is often zero. And you want it fast and efficient.

Buy an electric electric screwdriver for daily household chores. the best solution. Not to mention the fact that it is indispensable for professionals. It is used on construction sites, for repairs, and in furniture shops. With the help of an electric screwdriver perform installation of drywall structures, installation of windows and doors, fixing baseboards and furniture assembly.

It is a gross mistake to choose an electric screwdriver based solely on its cost. They differ in power and different functions. In order not to make a wrong choice, you should carefully study its technical characteristics before buying. The main ones are rotation speed, torque, and battery type (in a cordless tool). But reading the numerical data. half the battle, you need to know how to navigate, which indicators are needed for you and for the planned work.

Eliminating the memory effect

Not always the restoration of the battery screwdriver requires some radical action. It often helps to restore the capacity of the battery by alternating between full charging (until the charging lamp goes out) and full discharge of the battery. This method is also called “rocking the battery”.

How to erase the memory effect of the battery

It is connected with the so-called “memory effect” and is characteristic of nickel batteries. And it is especially strong in nickel-cadmium batteries. It occurs when a battery that has been discharged to zero is not fully recharged and begins to run or vice versa. This causes the crystals of the active substance to enlarge, which reduces the active surface area of the battery.

Observe the manufacturer’s recommendations for charging and discharging modes.

It can be eliminated or considerably reduced by so-called “training” of the battery. It consists of the repetition of full charge and discharge cycles.

For this purpose, the battery to be regenerated is completely discharged, e.g. by using a light bulb. Then charge it fully and discharge it again. Repeat the process 5 times and if individual elements of the battery are correct, the characteristics will return to normal or close to it.

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Lithium-ion batteries are probably the most common and unpretentious. The peculiarity is that they should not be fully discharged (no more than 80%). Designed for 3,000 cycles. Guaranteed service life is about 3 years, although for some models up to 10 years.


Conclusion. it is advisable to purchase for systematic (even more so daily) use. For household purposes, if you only have to use the electric screwdriver occasionally, there is no point in buying.

How to properly charge a new battery for the first time and during training

How to charge the screwdriver the first time after purchase? Many manufacturers of screwdrivers with lithium batteries (Li) recommend simply fully charging the cell before the first use. Few recommend to perform 3 training cycles. charge-discharge. In general, for lithium batteries a training cycle is useful.

Warning! For new nickel batteries and Cd and MH batteries, all manufacturers strongly recommend that you do the training cycle at least three times. And it is very important to discharge first, and then charge.

Unfortunately, none of the manufacturers, not even Bosch, writes about the correct way to discharge the battery during the training cycles. It has already been mentioned above why this is important.

If a power tool with Ni-Cd and Ni-MH batteries has deep-discharge protection, it is discharged before the screwdriver is turned off. If there is no protection, then to the minimum voltage level. This is 0,9V for each battery cell in the battery.

Lithium battery powered wrenches are always protected against deep discharge, but it is helpful to know that the minimum voltage should not be less than 2.8 V. Below this threshold, lithium cells are destroyed. Manufacturers are insured and set the disconnect limit at 3.2-3 V.

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You can read more about proper charging of screwdriver batteries in this article.

To summarize everything mentioned above in this article, let’s outline the order of the training cycles that are also useful for a new battery. It is recommended to do such cycle at least once in 6 months, better more often.

  • discharge the battery with 0.1 current of its capacity or with the current of a running tool without load. alternating a 3-minute run time and a 3-minute pause.
  • Charge the battery before turning off the charger.
  • Wait 20-30 minutes.
  • charge again until the charger has been disconnected.
  • Wait again for 20 to 30 minutes.
  • Charge a third time until the charger is disconnected.
  • Wait 20-30 minutes for the voltage to stabilize.
  • Now discharging by the method described in p. 1.
  • repeat step. 1-8 up to three times.
  • either top up or fully charge it for storage, taking into consideration the battery type. If the tool will be used in the near future, charge it fully before turning off the charger.

Recommendations for battery charging from manufacturers: Sturm (Ni-Cd), RedVerg (Li-ion), Hammer (Ni-Cd)

Repacking Makita 18v Lithium battery with New Cells (Save ‘s)

The right way to charge your electric screwdriver: how to do it better

There are a few simple rules on how to charge an electric screwdriver battery so that the tool uses up all of its possible life.

When you purchase a new tool, remember to put the battery on charge before using it for the first time. All batteries have a tendency to run out if they have been sitting in the warehouse or in the store for a long time. If your electric screwdriver is equipped with a Ni Cd (Nickel-Cadmium) cell battery, charge it fully and then discharge it 3 times to eliminate the memory effect common to Ni Cd batteries and bring the battery capacity back to an optimal level.

If your electric screwdriver has lithium-ion batteries, they do not need to be pumped because they do not have a “memory effect”: they are more modern batteries.

You should charge the battery at a favorable ambient temperature. The best temperatures at which the battery of an electric screwdriver should be charged are at least 10°C and not more than 40°C. The battery should not be left unattended for too long while charging to avoid overheating and overcharging. Although, if the standard tool is equipped with a process control indicator, the device will automatically “finish” the process when it is needed.

It is not advisable to leave the battery pack in the charger for a long time. And if you don’t use your electric screwdriver that often, it’s best to remove the batteries and store it separately. In case the batteries are not used for a long time, make sure they are in a charged state by “recharging” them once a month for 25-30 minutes.

As you know, the battery pack of an electric screwdriver comes in either a nickel-cadmium or lithium-ion. Ni Cd batteries can be stored at any state of charge. Their main advantage is that they are not afraid of deep discharges. For them to work well after a long break, they should be “pumped” three or four times as usual. The “pumping” time is, on average, 3-4 hours. during which you can work with an electric screwdriver as usual. It is desirable during the work of an electric screwdriver to control that the Ni Cd battery is not discharged partially but completely. This will help it not accumulate the same “memory effect”.

If the accumulator power unit of your tool is completed not by nickel-cadmium, and lithium-ion batteries, their main “plus” consists in the fact that they have no “effect” of memory. But it is recommended to watch their state of charge more carefully. In the case of an electric screwdriver with a lithium battery not used for some time, they need to be periodically recharged. They do not like deep discharges. If lithium batteries are exposed to deep discharge, the safety controller inside the battery pack will trip. To prevent this from happening, make sure that the batteries are at least 50 percent charged.

Specifications of the cordless electric screwdriver

The main technical parameters for batteries are capacity and voltage. the greater the capacity of the battery measured in “ampere-hours” (Ah), the more electricity it can store and the longer the tool will run off-line. The battery capacity of 1Ah stated in the product data sheet means that it can deliver 1A current for 1 hour.

The higher the battery voltage, measured in “volts” (V), the more power and performance the tool will have. Electric screwdrivers can use batteries with 3-36 volts. Batteries with bigger voltage are used in powerful tools for drilling holes of big diameters or driving screws into hard materials. Low-power tools with 3-6V batteries are used for drilling thin holes and screwing thin screws into not very hard materials.

the most popular screwdrivers among users of household tools are those with built-in 12-volt batteries, because they have the best ratio of cost, running time and power. When using the device, you should keep in mind that optimum performance and tool life are ensured only when using the battery type indicated in its passport. If a lower voltage battery is installed, the performance of the screwdriver will be insufficient and if a higher voltage battery is used, the motor will wear out prematurely and the tool will break down quickly.

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The design of a cordless electric screwdriver

Maximum torque

The torque, measured in “newton per meter” (N/m) ratio, determines the force developed by the tool when turning the screw or drill bit and depends on the motor power and the spindle speed. The models used for household purposes have a maximum torque of 12-20 Nm while the professional wrenches can develop up to 100 Nm.

Maximum rotation speed

While a high RPM of 900 to 1200 rpm is required for drilling holes, a low RPM of 400 to 550 rpm is required for screwing fasteners. This problem is solved by the motor rotor speed selector or regulator. The higher the maximum speed of the motor rotor, the more productive the tool is. adjustment of the motor speed is usually achieved by changing the amount of voltage applied to the motor winding via a potentiometer controlled by a turn-on control button on the motor.

Type of chuck

Screwdrivers can be equipped with either a key chuck or a quick-action chuck. The second type, unlike the first, does not require a wrench to hold the bit and therefore saves time when changing bits. In addition, there is no need to constantly carry a key, which is often lost at the most necessary moment. However, the quick-action chuck is inferior in terms of reliability and fastening strength, and allows the bit to rotate if there is great resistance in the material.

Connecting a 12 volt electric screwdriver to an ATX power adapter

Cordless screwdrivers are very user-friendly and are widely used by professionals and do-it-yourselfers alike. The very first thing that usually goes out of order is the battery.

At the moment all power tool manufacturers have switched to lithium batteries, and it becomes more and more difficult to buy a new nickel cadmium battery for an old electric screwdriver, and the for these batteries are much higher than for lithium ones.

Of course it is possible to buy batteries from different services that sell Chinese goods. But it takes time until the parcel with “banks” arrives and again, it is a certain expense.

There is an alternative to buying batteries/drums. connect your electric screwdriver to the mains power supply and forget about a quick discharge of batteries. Power supply on Aliexpress.

There is a lot of inconvenience with the power cord, but you always have to sacrifice something.

What is the current consumption of an electric screwdriver

Before selecting a suitable power supply, it is necessary to understand how much current you need to draw. Unfortunately, manufacturers of cordless screwdrivers do not specify the current consumption of the motor.

Capacity of the battery itself in ampere hours, which is necessarily specified on the battery, does not allow us to understand how much current the electric screwdriver consumes in operating mode.

the maximum a manufacturer can give is the power in watts, but this is very rare, because usually the power is specified directly in the torque.

If power in watts is still listed, we can have an idea of the current consumption and choose the appropriate power adapter with a small current/power reserve.

To calculate the current it is enough to divide the power in watts by the working voltage of the electric screwdriver, in this case 12 volts.

So, if the manufacturer has indicated a power of e.g. 200 watts. 200:12 = 16,6 A. this is the current consumption of the electric screwdriver in operating mode.

But the specified power is a rarity and there is no universal figure characterizing all 12 volt screwdrivers. It should be understood that at full braking of the motor shaft, currents can greatly exceed the rated current and it is not easy to calculate this value.

At the same time, the analysis of different forums and my own experience showed that a 10A current is often enough to operate an electric screwdriver and perform many of the functions of tightening and drilling.

It is known that the inrush currents at full braking of the shaft can exceed 30A.

So what conclusion can be drawn from all this?? For an electric screwdriver is suitable power unit 12 V giving 10 A, if you can use a unit of 20-30 A, it is even better. These are average figures applicable to most screwdrivers.

Power supply

We will not consider the purchase of any units or transformers, if only to buy a new battery! We will consider the possibility of using what is at hand. I should say at once. the charger from the same electric screwdriver is suitable only for drilling over-ripe bananas, its power is too low.

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Ideally a step-down, powerful 12 volt transformer would work, such as one from a computer uninterruptible power supply. The power of such a transformer is usually 350-500 watts. But I do not have in the presence of such a transformer, but there were many computer power supplies. I am sure that if someone has various electronic stuff, computer ATX in it will be stashed.

This is one of the first representatives of computer ATX power supplies.

A computer ATX power supply is quite suitable for an electric screwdriver, the 12-volt current carrying capacity of the bus allows it to draw 10-20 amps.

I want to dispel a little myth. you can’t cram a unit into a battery case of an electric screwdriver, the ATX board is too big. You have to make a separate case for it or leave it in its original metal case.

The disadvantage of the native case is sensitivity to dust, and in fact even the smallest repair is a lot of dust.

Pretty weak unit, 12v bus load only 10A. If possible, it is better to choose units with a more powerful twelve-volt bus.


Before you take over the construction of a working design, you should test everything on its “knees”, to make sure the stability of the electric screwdriver under load and the absence of severe overheating in the power supply.

We take a computer power supply and we test it: we plug in a network, in an output bunch of wires we find green wire (they say it can be other color, but I always found green ones) and we short it with a jumper to any of black wires (all black wires on an output. general conclusion, in our case it is a minus). The unit should turn on and 12 volts should appear between the black and yellow wires. You can check it with a multimeter or by connecting any computer cooler to the above-mentioned leads.

If all is well and the unit is putting out about 12 volts on the yellow and black (-) pins, continue. If there is no voltage at the output, you should look for another unit or repair this one.

We cut the plug from the unit output and take 3-4 yellow and black wires coming from the unit and connect them in parallel. When cutting the plug, do not forget about the green starter wire, it should be shorted to the black. We have a 12 V source with a decent current carrying capacity of 10-20 A, currents depend on the model and capacity of the unit.

Now we need to connect our 12 V to the terminals of the electric screwdriver without battery, the polarity of the connection look at the battery. And check the electric screwdriver. idling, then slowing down by hand.

At this point, I encountered a problem: when you press the button fully, the electric screwdriver works, when you slowly, smoothly press the electric screwdriver button, the power supply goes into protection. To reset the protection, you must unplug the unit and plug it in again.

It won’t go at all, you need to correct this instability somehow.

I took the circuit board out of the case and hooked up an additional multimeter, to constantly monitor the voltage

Shocking Things With 300 9 Volt Batteries!

In my opinion, such a phenomenon may arise from the fact that the power supply and the electric screwdriver button are controlled by PWM controllers, because of the interference on the power wires, controllers somehow interfere with each other. Try to solve this problem with an improvised LC-filter.

Types of tools

Screwdriver. an important tool, without which no construction or repair work. In today’s market all available types, used for different purposes. Especially this device is useful for small domestic work. With its help it is easy to screw and unscrew fasteners (screws, screws, self-tapping screws), drill, and mix glue or putty.

According to the type of power supply, all screwdrivers are divided into:

  • Cordless, battery-powered. They make the screwdriver weigh more, but access to awkward places is much easier.
  • Networked: those that function by plugging into an outlet. Because of the power cord, they have a short reach, which can be increased with an extension cord.

Screwdrivers are also divided into groups according to purpose. Among them are:

  • Devices for construction or repair tasks;
  • Screwdrivers for workshops, automotive centers, production halls;
  • Tools for industrial plants and factories;
  • Models for domestic (home) use.

Domestic, professional and semi-professional tools are sold in stores. When buying, they focus on the torque. It refers to the number of tasks the device can solve.