How to store ni cd electric screwdriver batteries

Features of charging nickel-cadmium batteries

Immediately before using any power tool, you need to study the instructions with the recommendations of the manufacturer. All tool brands such as Makita, Metabo or Interskol have them.

In these instructions for charging nickel cadmium batteries, you will find a number of similar points:

• it is necessary to charge the battery taking into account the temperature regime (the air temperature is not lower than 5 degrees);
• it is advisable to store a charged battery separately from an electric screwdriver so that contacts are not oxidized;
• monitor the charge level using an indicator built into the charger;
• Nickel-cadmium batteries are always charged to the maximum and discharged to the minimum.

How to store the battery

Any master who is careful with power tools is worried about how to properly store the battery from an electric screwdriver. Compliance with the rules of maintenance applies to all types of batteries.

• If you decide to send the electric screwdriver for storage, then before that it is worth discharging and charging the tool several times.
• The optimum positive temperature for storing the battery is 10 degrees. Freezing of the appliance must be avoided.
• Charging is recommended every six months. This procedure extends battery life.
• It is advisable to disconnect the power source from the electric screwdriver, while removing all dirt from its surface. Remove oxide from contacts with a special cleaning agent or alcohol-based liquid.
• Nickel cadmium batteries should be slightly discharged. This is done due to their rapid self-discharge.
• Avoid exposure to direct sunlight and moisture. High temperatures can melt the plastic housing and cause damage and loss of efficiency. Water ingress will also damage the internal battery cells.

Experts in such cases recommend overclocking such batteries. To find out what is the reason for the decrease in work efficiency, the battery is disassembled, problem areas are calculated. Then the cells are charged again. For charging, first a large current is selected, then, after another discharge, a small current.

If electrolyte remains in the batteries (it may evaporate), such a procedure will help to reanimate the battery.

How to store nickel cadmium screwdriver batteries

The performance of cordless screwdrivers is the same as for networked models. The advantage of cordless types of screwdrivers is their mobility. However, in order for a power tool to serve for more than one year, it is necessary to figure out how to properly store its battery. In particular, know how to store NiCad screwdriver batteries.

How the battery of an electric screwdriver works

A rechargeable battery is a chemical current source used to operate cordless types of power tools. The accumulation of electricity occurs due to the electrolysis taking place in the battery. This process creates a constant voltage of the required level.

The voltage in the battery arises from the potential difference between the cathode and the anode. The unit of capacity is the ampere hour. This value shows the amount of current that is provided by the battery in an hour.

The device of the battery pack (battery) does not depend on the type of model of the electric screwdriver.

It includes the following structural elements:

• the case on which the contacts are located;
• series-connected power supply elements (batteries);
• thermistor that protects the battery pack from overheating.

Thermistors are not available on all models. Tool body, two-piece, plastic. It houses a dozen energy storage devices (in some cases there are more). Batteries are connected to each other in a single serial circuit.

The extreme terminals are connected to the contacts located outside the housing. These contacts connect the tool to the charger. The output voltage of the battery pack is the sum of the voltages of the strings of batteries.

There are four contacts outside the battery case:

• two power contacts (positive and negative), the purpose of which is to charge and discharge the battery;
• contact located at the top to control the thermistor;
• a contact capable of charging with the help of a special station and equalizing the sizes of charges of each storage unit included in the block.

There are rechargeable batteries of the following types:

• Nickel metal hydride (or Ni-MN). They have an output voltage of 1.2 V. Manufacturers of such batteries position them as environmentally friendly. This applies to both production and further disposal. Despite the small dimensions compared to other types of batteries, they have a larger capacity. Another plus of this type of drives is performance at low temperatures. The disadvantages of Ni-MH batteries include high cost, limited service life, and increased self-discharge. When working, it is not recommended to discharge them completely.
• Lithium ion (or Li-ion). The voltage of this type of battery is directly proportional to the number of storage units included in the battery. The range is from 1.2 to 3.6 V. Li-ion batteries have a control board and a special controller that monitors all power supply links entering the unit. The advantage of lithium batteries is the absence of a “memory effect”, large capacity, low weight. Lack of “memory effect” allows you to charge the battery as needed. It is advisable to charge it well before prolonged work. The charge can be stored for a long time if the battery is at least half charged. The disadvantages of this type of batteries include their high price, short service life, and the inability to work at low temperatures. Batteries of this type are the most common. most construction tools are equipped with them.
• Nickel-cadmium (or Ni-Cd). This is the battery standard for all power tools with battery. The advantages of Ni-Cd-type batteries lie in their: low price, fast charging function, maximum load current transfer function, the ability to maintain a high capacity at temperatures below twenty degrees, the ability to perform a charge-discharge cycle up to a thousand times.

How to charge batteries to extend battery life

To properly charge the battery, remember the following:

• It is best to charge the battery when using the tool for the first time. It happens that they are discharged during storage.
• For nickel-cadmium batteries, the maximum capacity appears after the third charge-discharge cycle. Then the drive is charged when the minimum power occurs.
• Lithium-ion batteries are recharged as needed, regardless of charge level, as they have no “memory effect”.

If you do not neglect the information on how to store Ni-Cd batteries in screwdrivers, you can significantly increase the service life of the tool.

General charging rules

When charging the battery of a construction tool, the following rules must be observed:

• The battery should be charged indoors at a temperature of 10 40 ° С.
• To prevent overheating during the accumulation of charge, you can disconnect the battery from the network from time to time (if there is a built-in thermistor, this measure is not required).
• New drives should not be installed on an electric screwdriver without first charging and checking with a multimeter.
• You need to recharge the battery immediately after it has sat down: during self-discharge, the voltage may drop below a critical level, as a result of which the drive will fail.
• Do not leave the battery connected to the network after the charge is restored: the recommended time interval between the end of the process and shutdown is no more than 20-30 minutes.

The charging time can be from 0.5 to 6-7 hours, depending on the type of drive and the degree of discharge. When using a pulse charger (charger), it is reduced to 60-100 minutes.

How to properly charge new lithium-ion batteries in a screwdriver?

One of the most popular tools among home craftsmen can rightfully be called an electric screwdriver. And this is no coincidence. with its help you can not only tighten / unscrew screws / screws / self-tapping screws, but also drill small holes, and using special attachments, you can grind and polish surfaces and even sharpen the cutting tool.

Another feature of screwdrivers is their mobility, that is, it is not at all necessary that there is an outlet nearby. It is enough to purchase an electric screwdriver with a battery.

But this is where the lack of cordless screwdrivers comes to light. In order to work successfully with such a tool, you need to have a battery with good characteristics and ease of maintenance.

Until now, nickel-cadmium batteries have proven themselves well, but recently they have been replaced by lithium-ion.

And if users about the first have more or less complete information about the properties and maintenance procedure, then the second type has a lot of questions and one of them is how to properly charge lithium-ion batteries and how to store them when they are not in use.

In everyday life, users have the opinion that before starting to work with the battery, it is necessary to carry out a three-fold “discharge-charge” cycle. This is true for Ni-Cd batteries, but not for Li-Ion.

First of all, it should be noted that lithium-ion batteries, unlike nickel-cadmium batteries, do not have a memory effect, and, therefore, they can be charged at any stage of discharge (including immediately after purchase). It is for this reason that manufacturers send them on sale charged 3/4 of the norm.

But still, to extend the guaranteed service life, some rules must be followed:

1) Li-ion should be charged with a residual charge of 20-50%;

2) attention!. it is unacceptable to discharge lithium-ion batteries below 10-20%. For them, this is a critical value, but it should be borne in mind that the lower the degree of discharge, the more discharge-charge cycles they will withstand:

3) Li-ion should be charged at a temperature of 10-30 degrees, and operated in the range from minus 10 to plus 45 degrees;

4) once every 4 months, you need to carry out a full cycle “discharge-charge”, discharging the battery to almost zero, and then put it on charge for 12 hours. This is necessary to calibrate the charge level sensor in the battery controllers;

5) another feature of lithium-ion batteries is that they cannot be stored fully charged for a long time, otherwise they will permanently lose 20% of their capacity in just three months. Send the battery for long-term storage with a charge of 40-60% of its full capacity, and then it will lose only 1% in the same three months;

6) If you have two batteries in the kit, then charge one of them to the recommended value (40-60%) and send it to the reserve for a month, and after this period, charge up to 100%, use it in work until it is discharged to 40-60% ((or artificially discharge) and send back to storage for another month;

How to revive dead NiCd battery from cordless power tools

7) Let the second one be your main worker and, if you worked it intensively, put it on charge, even if it is discharged by less than 10%.

If you completely follow the recommendations recommended by the manufacturers, then most likely you will not need to buy a second battery at all, since the service life of an electric screwdriver and a lithium-ion battery is almost the same. Well, unless you are a professional worker, for example, in the assembly of furniture, when one battery cannot handle the entire shift, then a backup battery will be needed.

How to Store Lithium Ion Electric Screwdriver Batteries

electric screwdriver with a lithium-ion battery: description, characteristics, operation and repair

Since the period when the electric screwdriver has become an inventory that is found in the arsenal of not only a professional builder, immediately a home craftsman, the issue of choosing this equipment has become a burning issue. This device can be networked or rechargeable. The latter type is very popular when you often have to work in a place where there is no ability to connect to electricity.

Li-ion

Li-Ion technology is advanced today. Lithium cells are much more compact and lighter than the previous ones with the same electrical capacity and, which is very convenient, can be charged with an increased current. At the same time, the time to fully charge lithium-ion batteries can be reduced to 1-2 hours.

A big advantage of this type of battery is the almost complete absence of memory effect. the instrument can be recharged at any time and to any level. Self-discharge of a Li-Ion battery is relatively low and amounts to approximately 2-3% of its capacity per month.

As for the shortcomings, until relatively recently these were high degrees of fire and explosion hazard. If used improperly, the battery could catch fire or even explode. over, the burning element is almost impossible to extinguish with water. this only intensifies the combustion.

Another serious drawback of cells of this type is that they do not tolerate deep discharge and overcharge. In the first case, the battery immediately fails, in the second, it can catch fire. But this problem was also easily solved with the same controller, which disconnects the battery from the load during a critical discharge and from the charger if the battery is charged.

Typical Li-Ion battery life is 600 charge / discharge cycles, but it is also highly dependent on “age”. A lithium-ion battery can be stored for no more than 2-3 years, regardless of whether it works or just lies on the table.

When choosing a tool with such batteries, it should be borne in mind that they will behave badly in the cold (a strong decrease in capacity, which, however, will recover in warmth). In addition, they will not be able to deliver a large current at any temperature, which means they will not provide the large torque required for working with dense materials. And the cost of Li-Ion cells is much higher than that of nickel counterparts.

USB & Li-ion Upgrading dead Black & Decker Screwdriver. 892

Nickel metal hydride

This type of battery appeared a little later. in the early 90s of the last century. Ni-MH cells have similar characteristics to cadmium, but the memory effect is much weaker (but still manifests itself) and, most importantly, there is no cadmium in such batteries.

Ni-MH battery for electric screwdriver

A nickel-metal hydride battery is capable of delivering a decent current, works well in cold weather, and its self-discharge is the same 7-10% per month. As for the cost, batteries of this type are somewhat more expensive than cadmium ones, while the number of charge / discharge cycles, on which the service life depends, is only 300-500 times, which is a significant disadvantage. The shelf life of such elements is 6-7 years. The size / capacity ratio, as well as the charging time. up to 8 hours, is similar to cadmium. Metal hydride elements, like cadmium, tolerate deep discharge well.

1997 NiCd Cordless Screwdriver Teardown (It still works after 20 years!)

What does the battery voltage say?

For cordless models, the power and rotation speed of the electric screwdriver depend on the battery voltage, which must correspond to the parameters of the tool:

• For screwdrivers, the maximum indicator is 36 V. These are the most powerful devices for working with metal and hard wood.
• 12-18 V. average value, suitable for most processes in repair and installation.
• 3-10 V. refer to low-power, and are used only for assembling soft materials or small diameter fasteners.

Installing a battery with a higher capacity on a weaker model will damage the latter faster. A 12 V battery on an 18 V device will, on the contrary, limit the power of the tool, so the voltage indicator of the drive must exactly match the value on an electric screwdriver.

Keep in mind that if you take two batteries with the same capacity, the longer operation of the tool will be provided by the one with the higher voltage.

Recovery with high current

You can also restore the battery using a pulse discharge.

Devices required for recovery:

• Multimeter;
• Power supply;
• Means of protection.
• We disassemble the battery of the device and measure the voltage of the poles of each can.
• We connect the negative terminal to the power source. for this you can use a car battery or an uninterruptible current source with a voltage of 12V. If you are restoring a battery with a voltage of more than 9.6V, then you need to use a circuit of 2 batteries.
• Attach the other cable to the positive pole.
• Connect the power supply to the positive pole for a short time. It is recommended to connect for 4-5 seconds so that the cable does not weld to the power source.
• We measure the voltage at the poles of the bank, if it has not increased, then we reapply the current.
• We carry out several charge-discharge cycles to restore the battery capacity.
• The disadvantage of this method is that after several tens of discharge cycles, the capacity of the battery decreases, since self-discharge occurs during feeding, but this does not restore the chemical composition of the working fluid of the electrolyte.