Choosing a screwdriver
When choosing a screwdriver, make sure the ease and ease of use. Feel the grip in your hand. But first it is necessary to decide for what purposes we need a screwdriver.
For use at home or in the country, a network screwdriver may be enough. The fact is that with infrequent use, we do not have to overpay for a fancy screwdriver. By choosing a rechargeable Ni-Mh or Ni-Cd battery, you can get long life batteries for little money. It is not necessary to take Li-Ion batteries for home, i.E. They require constant use, moreover, their cost is much higher. But it all depends, of course, on the wishes and capabilities of the buyer. If the means allow, then you can consider powerful screwdrivers from well-known tool manufacturers with some additional capabilities.
If a screwdriver is necessary for professional use, then no doubt I choose a Li-Ion battery for it, which, if used correctly, is able to provide a high-quality screwdriver High torque power and the required capacity for work.
How to replace battery cells and finish repairs
Replacing used supply units requires care. When buying new ones, check the correspondence of the used elements to the new ones, their parameters must strictly match.
Before You Begin Prepare the necessary tools and materials:
- Soldering tool;
- Tin;
- Alcohol rosin flux, low corrosive flux is suitable.
Further work is to eliminate the connections of the used elements and replace them with new ones. It is important NOT to delay the soldering process, which will lead to overheating and damage the battery.
For the connection, use existing or copper conductors, but of the appropriate section. A sequential circuit is assembled, in which the connection goes from the “plus” of one unit of the circuit to the “minus” of the next. The soldering must be of good quality and provide a good and reliable contact. Otherwise, the connection may heat up, negatively affecting battery performance.
After completing the assembly, the potentials of all components are equalized. This is accomplished by charging and discharging the power supply several times. In total, the magnitude of the potentials on each “bank” is approximately 1.3 V. These actions equalize the voltage in all sections of the electrical circuit and ensure the normal functioning of the device.
Such measures, carried out 2 or 3 times during a month, increase the life of the screwdriver.
Using the above information and recommendations, try to fix the battery for a screwdriver with your own hands.
Drills, hammer drills, screwdrivers with lithium batteries, indispensable for work in the factory
Cordless hand-held power tools have become, especially in recent years, no less popular than the traditional mains-powered power tool. This is explained by the possibility of its long battery life, ease of use, and the absence of the need for extension cords. However, along with this, the problem arose of choosing the most effective battery power source, which allows to ensure the maximum duration of the tool’s operation without charging, while maintaining the nominal voltage.
Battery for screwdriver
According to the power source, there are two types of screwdrivers: network and battery. Let’s take a closer look at battery.
There are the following types of batteries for screwdrivers:
The most common die-cast ion batteries for screwdrivers. Today, such batteries are used in many construction tools. Let’s consider it:
Which battery for a screwdriver is better?
There is a large selection of cordless screwdrivers on the tool market. All types of batteries are good in their own way. Each of them is suitable for certain conditions and duration of work. As well as the material with which to work.
Choose a mobile battery that can be removed for recharging. With such a battery, you are NOT limited in the working area, plus you are NOT energized and you can work with it in hard-to-reach places. Non-removable batteries are found only in low power screwdrivers. cordless screwdrivers. They are chosen, as a rule, for a large volume of work and on hard materials.
Most often, a second battery is included with the screwdriver. This is convenient, as you can work, and not come off the battery charge. Pay attention to the capacity of the battery, as the larger the capacity, the longer the operating time of the screwdriver. The capacity is characterized by an average value, which ranges from 1.3 to 3 A / h. At home, 1.5 A / h is enough for you to work with simple materials. If the screwdriver is idle for a long time, the battery capacity of the tool will inevitably decrease. In about a year, half or even more.
If you are looking for a screwdriver for household work, then the weight of the tool should be up to 2.5 kg. Charging such a battery takes from 1.5 to 6 hours, it all depends on the model you choose. A professional tool is characterized by shock power, they are usually heavier, but it charges faster in an hour.
Whichever type of screwdriver you choose, the main thing is that it is comfortable to hold in your hand.
Nickel cadmium batteries for screwdrivers
Nickel-cadmium batteries are most often installed on household screwdriver models, they are designed for 1500 charges.
Voltage 1.2 volts. DOES NOT get hot when charged with high current. The shelf life is five years. Works at a temperature of 15 degrees cold. Stored discharged. Has a memory for a charge, so it is necessary to discharge the battery completely so that the capacity does NOT decrease.
Nickel metal hydride batteries
Nickel-metal hydride batteries have a higher capacity compared to nickel-cadmium batteries. Lasts for 1000 discharges. The advantage of this battery among the rest is that by itself it practically does NOT discharge.
It has no memory for charge, the voltage, as well as in a nickel-cadmium battery, is 1.2 volts. In fact, Ni-Mh is a cross between the two batteries described above. Stored charged. However, before work, the battery is discharged and will recharge.
Rules for working with the tool
I bought a screwdriver, read the operating rules so that it will last a long time. Charging is required immediately. How to properly charge a screwdriver battery? It depends on the type of charger.
Nickel-cadmium are charged up to 3 times. The new power supply does not have full capacity, charging increases it to full capacity. During operation, the subsequent replenishment is performed after the power has been reduced to a minimum level.
Lithium-ion batteries have a memory effect, so they are powered at a convenient time, do not bring them to final discharge.
Pay attention to the ambient temperature to ensure the device is properly charged. Its range is 10-40 degrees Celsius.
For trouble-free battery operation, follow these guidelines:
- Do not allow overheating, this is bad for the operation of the instrument, if this happens, stop work and cool the device;
- The battery is disconnected from the apparatus and stored;
- With rare use, the battery is charged NOT more than 1 time per month;
- When you turn it on for the first time, you cannot completely discharge the battery, a drop in charging will be indicated by a decrease in the device’s speed.
Fulfillment of THESE points will allow you to correctly use the unit.
How much to charge the battery? The charging time is given in the passport. Often a display system is included with the charger. She monitors the charging process and determines its end. Usually the whole procedure lasts 7 hours.
How to check the battery
The battery is an energy storage device and provides a direct current supply to the circuit due to the chemical transformations of reagents into electricity taking place inside.
How to check the battery? To do this, pay attention to its characteristics. One of these indicators is the capacity of stored energy. It determines the amount of current that the device will give per unit of time. A / Time.
The difference between the poles on the battery is equal to its voltage.
The battery test reveals the quality level. In case of inoperability will determine its cause.
Required test tools:
- Voltmeter 15 V DC;
- DC ammeter;
- Multimeter;
- Tester.
They put the device on charge and take measurements after a selected period of time. Usually, after 0.5 hour, the voltage value increases to 13 V. If after 2 hours the device shows 14 V, this indicates a good battery condition, since a fully charged unit has a voltage corresponding to 17 V.
With a voltmeter or tester, determine the potential at the poles. In the absence of load, the result is equal to the magnitude of the potentials at idle, approximately 17 V. A lower value will indicate either the presence of idle cells, or incomplete charging.
Then we carry out a load test. It will allow you to find out the battery discharge time. The size of the load must correspond to the power of the device. It can be calculated using the formula:
Where I is the operating current of the battery, in A (amperes)
U is its voltage in V (volts).
The load will be a 12 V lamp or a 35 V car headlight with a power value of 35 to 40 W.
Connect the device through an ammeter to a lamp or headlamp for three minutes. If the value of the measured voltage is between the values of 12-12.4 V, then this indicates the presence of a damaged element. This defect will be reflected in the lamp. Its brightness will decrease. And the lamp completely extinguished during the test indicates a small storage capacity, since it was quickly discharged.
The voltage should be 23 V, a lower value indicates insufficient supply capacity.
Lithium Ion Batteries
The voltage of the lithium-ion battery is 3.6 volts, the battery weighs little, charges quickly and has no memory to charge. To get good performance and performance, the battery must be constantly used. Li-ion battery life is three years.
The effect of storing the charge level
This phenomenon is called “memory effect”. If the battery on the instrument was NOT completely DISCHARGED and then put on charge, the residual charge level begins to be perceived by the battery as zero. After being charged to a full stage, it will function until the energy supply reaches a new level, and after that it will report that it is DISCHARGED, although the container will NOT be completely emptied.
In view of this phenomenon, the master has to make sure that the battery is completely discharged, and only then puts it on charge. This is not always convenient if there is still a charge at the end of the day, and tomorrow there is a lot of work. All types of nickel batteries have a memory effect. But lithium-ion models can be charged at any time. they will always consume the accumulated energy to the end, without spontaneously reducing the capacity.
Lithium-ion (Li-Ion)
One of the new generations of batteries, which first appeared in 1991. Japanese radio engineering companies began to actively use them, and subsequently they managed to increase their power and use them with power tools.
It is this type that is used in mobile phones, laptops and electric vehicles. The cathode and anode in them are made of aluminum and copper foil, between which a perforated separator is installed. A valve may be present to release internal pressure.
Battery selection based on application
So, having thoroughly examined all the key factors, we will discuss with which battery to choose a screwdriver for home and professional activities. This will help you NOT overpay and have a reliable tool at hand.
For home use
To quickly disassemble household appliances, a knot in the car or screw a couple of sheets of drywall at home, a small capacity of 1.5-2.0 Ah and a voltage of 12 V is enough. By the type of battery, for household use, Li-Ion is suitable, which holds a charge better and is always ready to work ? Even after long-term storage. It is optimal to have two batteries and alternately install them on a screwdriver, this will increase the autonomy time.
Which batteries are best for a screwdriver. an overview and comparison of all types
To find out which batteries are best for a screwdriver, consider their types and characteristics, and also compare with each other. This will help you choose the right type of battery, which will be able to deliver the required power and provide power to the tool for a long time.
The cost
For the price, the cheapest batteries for a screwdriver are NiCd. The second place is taken by NiMh. Replacing the battery that has spent its resource will NOT be expensive for the master.
expensive are Li-Ion batteries, which sometimes cost up to 50% of the price of the screwdriver itself.
Nickel Metal Hydride (NiMh)
This type is most often used in AA batteries. They began to be developed in the late 1970s. The main substances for the accumulation of charge and its recoil are nickel-lanthanum, which serves as an anode, and nickel oxide, which is a counterpart, the cathode. Ion transfer is provided by potassium hydroxide.
Full discharge ratio
This is an important aspect that affects the life of the battery, which can be significantly reduced from improper use. All modern lithium batteries cannot be fully discharged. The optimal storage condition is 40% charge. If you generate all the energy to 0, then this can completely disable the drive.
Therefore, such elements need to be recharged even if the tool is still working well. Both types of nickel batteries tolerate full discharge well and can be operated until the screwdrivers stop turning.
What does the battery capacity say?
Battery capacity is written in numbers from 1.0 to 7.0 and is measured in amperes times hours (Ah). The value is deciphered as follows: The specified number of amperes can be delivered by the drive within an hour. But since no screwdriver consumes 1-5 A during the time, the time of its use stretches from 2 to 8 hours. The higher the capacity, the longer the tool can stay in use.
Replacing batteries with similar ones
On some blocks you can see the fixing screws, which need to be removed. But on most battery blocks there are self-tapping screws, since the body is glued together. To open such a block, you need to carefully insert a screwdriver into the gluing place (shown by an arrow in the photo) and press lightly so that the walls of the case are disconnected. The same actions need to be done around the entire perimeter.
After opening the block, you will see the batteries in it.
- You need to solder quickly, do not allow the battery to heat up, as it may become unusable.
- For connections, you need to use “native” plates, desoldering them from the old batteries (they have the desired section and resistance).
- It is important to correctly connect the plus and minus of the battery. The elements must be connected in series: the minus of the previous battery must be connected to the plus of the new one, and the minus of the new battery to the plus terminal of the next battery.
After connecting all parts, it is necessary to equalize the potentials on all batteries, since they are different. Carry out one charge-discharge cycle: Connect the charger to the battery overnight, then let it cool down for a day and measure the output voltage in turn on all cells. If everything went well, then on all batteries the indicator will be the same. within 1.3 V.
Now the battery needs to be discharged, inserted it into the screwdriver and the latter is loaded to the maximum. The main thing is NOT to overheat the engine of the tool. Give him a little rest. Bring the battery to full discharge. Repeat this procedure 2 more times (full charge and full discharge).
Replacement with lithium batteries
Replacing NiCd cells with Li-Ion is also not difficult. It is known from the school course that if the batteries are connected in series, then their voltage ratings will be summed up. For example, your screwdriver runs on a battery with a voltage of 14.4 V, which means that it can be replaced with four 3.3 V finger batteries. This voltage will be enough, because lithium batteries DO NOT “sag too much” when starting the device.
It is recommended to buy batteries from reputable manufacturers, for example, Sistem A123. The LiFePO4 battery of this company has a capacity of 2400 mAh, sufficient for the normal functioning of the screwdriver. If you buy batteries via the Internet, then they will cost you less. around 900 rubles for 3 pieces.
You will also need to purchase soldering acid instead of alcohol flux. In this case, overheating of the batteries will be minimized. The soldering iron must have a power within 65W.
You can learn more about how batteries are replaced with lithium batteries by looking at this.
Which battery for a screwdriver is better to choose
A cordless screwdriver is a fairly convenient and popular tool. Independence from the power supply makes this device mobile and allows you to work in hard-to-reach places. But despite all the advantages, the rechargeable battery (AKB) is the weak link in a screwdriver. Therefore, when choosing a power tool, you first need to understand what types of batteries exist, what is their difference, the pros and cons of different types of batteries.
Nickel-cadmium batteries
This type of battery is the most common, although it is over 100 years old. Nicd batteries have good capacity and low cost.
Nickel-cadmium batteries have the following advantages.
- Durability. With proper operation, the battery can last 8-10 years.
- Ability to work at low temperatures. The battery power is practically NOT reduced, which allows you to use the tool in the winter outdoors.
- High degree of reliability and unpretentiousness to working conditions.
- The battery can withstand a thousand charge-discharge cycles.
- The battery can be stored for a long time in a discharged state.
Since NiCd batteries are not “afraid” of a full discharge, you can work with the tool at a complete stop, that is, until the battery is deeply discharged. Only then can you put it on charge, and not fear that the battery capacity will decrease.
However, nickel cadmium batteries are NOT without drawbacks. Toxicity of internal battery filling causes disposal problems.
Batteries of this type are quite heavy when compared to other types of batteries. In addition, they have a “memory effect”. This phenomenon occurs in a nickel-cadmium battery when it is prevented from fully discharging. If you turn on such a battery for recharging, then it will “remember” this value and during further work it will be discharged to this very mark. This will lose a significant portion of the battery’s capacity. The figure below clearly demonstrates how the “memory effect” appears.
Varieties of batteries for a screwdriver
There are 3 types of rechargeable batteries on the power tool market:
- (NiCd) nickel-cadmium;
- (NiMH) nickel metal hydride;
- (Li-Ion) lithium-ion.
Li-ion batteries
Li-Ion batteries noticeably win most positions in the second types of batteries. The advantages of lithium-ion batteries include the following:
- Almost complete absence of the “memory effect”;
- You can recharge the lithium-ion battery at any stage of discharge, without fear of loss of capacity;
- Comments on power loss at low battery charge;
- Effective service life is 5-8 years;
- Low self-discharge;
- Takes little time to charge;
- No toxic elements;
- High power with small dimensions.
Cons of lithium-ion batteries:
- Shock sensitivity (may explode on strong shock)
- The unit does not tolerate full discharge and overcharge. this causes the battery to fail;
- Discharges quickly at low temperatures;
- High price;
- Service life is lower than in nickel-cadmium batteries.
It is difficult to say unequivocally which battery is better. Basically, you must decide for what purpose you are going to purchase a screwdriver. If for home use, which implies infrequent switching on with long interruptions in work, then you need to choose a tool with a nickel-cadmium battery.
Lithium-ion batteries are the professional choice. They are designed for continuous, long-term and continuous operation. The recharge time of the battery is also important for a professional tool. But it is worth remembering one rule: a lithium battery cannot be brought to full discharge.
Nickel-metal hydride batteries
Nimh batteries have been designed to overcome the disadvantages of nickel-cadmium batteries. The positive characteristics of nickel-mell-hydride batteries are as follows:
- Have smaller dimensions and weight;
- Have low toxicity;
- The “memory effect” is weak;
- Have high capacitive characteristics;
- Resistant to mechanical damage;
- Increased number of charge-discharge cycles (up to 1500).
However, NiMH batteries have their drawbacks:
- It is forbidden to use them at negative ambient temperatures;
- The battery tends to discharge quickly;
- Shorter battery life when compared to nickel-cadmium batteries;
- High price;
- Takes a long time to charge;
- The battery does not “tolerate” deep discharge.
Thus, although NiMH batteries were created to compete with nickel-cadmium batteries, they are significantly inferior in performance to the latter.
How can you replace the “native” battery in a screwdriver
If the batteries in your screwdriver are worn out, they can be easily replaced. There is such a thing as battery interchangeability. For example, under the PowerPlant brand, batteries are produced that are compatible with most popular brands of power tools. They cost much less than “native” batteries and are quite efficient.
But if this option does not suit you, then the batteries themselves in the unit can be replaced with new ones. To do this, you will have to disassemble the battery pack and remove the elements that make up it.
DIY screwdriver battery charger
If your screwdriver charger is out of order, or you have rebuilt the tool battery by replacing NiCd batteries with Li-Ion cells, then you will need to get a new charger. Below is a diagram of a charger capable of providing a charging current suitable for any type of battery.
This charger is a current generator based on the VT2 transistor. The latter is powered by a rectifier bridge. The bridge, in turn, is connected to a step-down transformer with the required output voltage. This transformer must have good power so that it can work for a long time without overheating, providing the required current. Otherwise, the transformer may burn out. The voltage supplied by the transformer does not have to be higher than 27 V.
The charge current is regulated by the resistor R1 (the battery for the screwdriver must be connected). It must remain constant throughout the entire charging process. Resistor R3 is designed to limit the maximum current. The VD6 LED will stay on as long as the charge is in progress. When the charging process comes to an end, the light of the LED will begin to decrease, and it will go out.
All elements of the electronic circuit are installed on a PCB made of PCB covered with a layer of copper foil. The diodes indicated in the diagram can be replaced with diodes extracted from old radio equipment, KD202 or D242. Parts on the board must be placed in such a way that there is no intersection. High density of placement of parts is not required. If you leave 3-5 mm between them, then it will be easier to solder. Be sure to install the transistor on a radiator with an area of at least 20-50 cm 2.
Based on the dimensions of the board, you will need to make a case (it can be made of plastic) using a glue gun. The table below contains the entire list of required radio components.
If you assemble the charger by following this diagram, you will get a reliable, simple and inexpensive charge for your screwdriver.