How to repair an electric screwdriver battery at home

Battery replacement in an electric screwdriver. types of batteries, defect identification, repair, replacement

Sooner or later the battery pack of an electric screwdriver will reach the end of its useful life. However, the price of a new battery is almost comparable to the cost of the device, and therefore the only inexpensive alternative is to replace the batteries in an electric screwdriver. Let’s consider what kinds of batteries there are and what their features are, how to quickly determine the fault, what recovery methods are available and how to repair or replace individual units if necessary.

Parameters of the choice of new cells

Choosing new cells is simple. in design, dimensions and capacity you need to choose exactly the same cells as the old ones. Then there should be no problems with installation, charging and operation. Due to improvements in technology, elements with similar seating dimensions, but greater capacity may appear on sale. They are undesirable, as they will require more time to replenish energy at the same current and will work in different conditions. In this variant it is possible to replace all the banks at once.

How to convert the battery to lithium-ion cells?

Often owners of screwdrivers running on nickel-cadmium batteries want to adjust the battery to lithium-ion batteries. Such popularity of the latter is quite understandable. They have many advantages over other options. These include:

  • the possibility of lightening the weight of the tool (it is more convenient to work with it if lithium-ion batteries are installed);
  • it is possible to eliminate the notorious memory effect, because it simply does not exist in lithium-ion cells;
  • the use of such batteries will charge several times faster.

In addition, we must also consider the fact that with a certain scheme of assembly of the device, it is possible to multiply the capacity of the charge, which means that the period of operation of an electric screwdriver from a single charge will significantly increase. The positives, of course, are obvious. But it must be borne in mind that there are certain drawbacks in the adaptation of equipment for lithium-ion batteries. It is important to take into account both. Consider what disadvantages you may encounter with such work:

  • Li-ion power components are more expensive than other options;
  • you will need to maintain a certain degree of charge of such a battery at all times (from 2.7 to 4.2 V), and to do this you must insert a charge and discharge controller board into the battery box;
  • Lithium-ion power components have more impressive dimensions than their counterparts, so it is not always convenient and trouble-free to place them in the case of an electric screwdriver (it is often necessary to resort to various tricks);
  • if you have to work in an environment with low temperatures, it is better not to use such a tool (lithium-ion batteries are “afraid” of cold).

If, given all the pros and cons, you have still decided to replace the nickel-cadmium batteries with lithium-ion ones, you should carry out the following procedures.

  • First you have to determine the number of lithium-ion sources.
  • It will also be necessary to choose a suitable controller board for 4 batteries.
  • Disassemble the battery case. Take out the nickel-cadmium cans. Be careful not to break any critical parts.
  • Cut the whole chain with wire cutters or side cutters. Do not touch only the upper parts with contacts necessary for connecting to the screwdriver.
  • It is acceptable to remove the thermistor, because the overheating of the batteries will then be “watched” by the controller board.
  • Next you can proceed to assembling the chain of lithium-ion batteries. Connect them in sequence. Next connect the controller board, referring to the diagram. Take care of the polarity.
  • Now place the prepared construction in the battery case. Li-ion type batteries should preferably be placed horizontally.
  • Now you can safely close the battery with the lid. Fix on the horizontally lined up batteries the power cell with the contacts on the old battery.

Sometimes it turns out that the assembled technique is not charged from the former charging unit. In this case you will have to install one more connector for the new charger.

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How to disassemble the battery

If a faulty battery is detected, you must move on to locate the faulty cells. all cells rarely fail at once, and one or more lagging cells are enough to cause problems. Therefore, the repair of batteries for an electric screwdriver must begin with the disassembly of the battery and removal of the cells. Do not disconnect them yet.

Disassembly procedure depends on the case design. Somewhere you will need to unclip the latches, somewhere unscrew the self-tapping screws or screws. After removing the lid, you need to take out the cells of the battery.

Before you disassemble the battery, you should conduct a visual inspection of each cell. If among them there are bloated, mechanically damaged, with traces of electrolyte leakage or corrosion, such cells should be immediately marked as faulty. There is no need to reassemble them.

On the other elements you need to measure the voltage. If it does not correspond to the nominal (or even below the lower limit), the bank must be tried to charge. Disconnecting the battery in this case is also not necessary.

You’ll need a voltage source with an adjustable output. If it was not possible to charge it, the bank is rejected. Cells that were successfully brought up to par value must be tested separately for capacity and current efficiency according to the methodology described above. If the battery can not hold a charge or does not deliver enough current, it is rejected.

The lithium-ion batteries must be charged with the balancer board disconnected. It can interpret a deep discharge as a malfunction, and block the cell.

How to independently perform restoration of the battery of an electric screwdriver

The ability to work with such a tool as an electric screwdriver, without connecting it to the mains. it is convenient, practical and, most importantly, necessary. You often have to do some work in places where it is almost impossible to reach the mains cable. Construction tool stores offer a wide range of screwdrivers, including Bosch, as well as the popular Hitachi and Makita. But, unfortunately, the battery life of any drill or similar tool is short. a maximum of 5 years. It happens that the battery of an electric screwdriver no longer charges and after a shorter period of time. It is not profitable to buy a new battery in a hurry. For the same amount of money you can buy a new electric screwdriver. Therefore, it is worth trying such an option as electric screwdriver battery recovery with their own hands.

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Repairing the battery of an electric screwdriver with battery replacement with your own hands

Hi! Today we will repair the battery of an electric screwdriver. Did you know that the history of electric screwdriver goes back to the Middle Ages. as far back as the 15th century, when knights were dressed in armor before the battle, and squires helped them twist armor parts with guess what? Screwdriver!

It was not until 1907 that Canadian inventor Peter Robertson patented the Robertson screw with a standard square hole that the screwdriver bit would fit into. Since then, screws have been produced on an industrial scale and used in the home. Later, in 1934, inventor Henry Phillips reworked the head of the screw and a cross cut screw was designed to fit the screwdriver. the motor had already been invented and the idea of the “screwdriver” was in the air. But there were big problems with batteries because of their weight and size. The problem was solved only in the 1980s when the first Ni-Cd and Li-Ion rechargeable nickel-cadmium cells appeared.

Production of household and professional cordless drills and screwdrivers was first mastered by USA and Japan. All of this is due to the emergence of new power-consuming batteries of electricity. Just them and will change urgently inside got in my hands cordless drill-electric screwdriver Interskol DA-10/10.8 ER. The problem was this. when you press the button motor just does not spin, but the LED lights up, but it shines weakly.

Restoring rechargeable cells

Here I will give a story from Master Sergei to restore the nickel-cadmium battery electric screwdriver. The owner began to complain about the short life of the electric screwdriver and the fact that the battery does not hold. Disassembly of the battery case showed that there are 1000 mAh Ni-Cd banks from the company Liang.

Ni-Cd battery can be restored in a fairly simple way. Need to do a few cycles of deep discharge and charge. In such extreme modes, hard-to-reach areas of battery charge accumulation, the return from which has deteriorated due to memory effects, abnormal conditions of use or storage, begin to work.

Such problems occur not only in screwdrivers. The battery-powered radio-controlled model industry solved the problems of automated discharge/charge long ago. There are special chargers for this.

At the master Sergei was Vista Power AK610AC. This is a battery charger with a 90 watt charge and a 20 watt discharge function. This is a great professional device with touch screen! You can find these on Avito for about 5000

Instead of such a charger you can use something more Chinese, such as the people’s IMAX B6 for about 2000

Start the cyclic recovery of the battery is best with a deep discharge and then immediately recharge.

After the first cycle, the capacity on discharge was 707 mAh, and on charge was 879 mAh. As you can see, the capacity has decreased by 30% compared to the manufacturer’s claims.

The second charge / discharge cycle showed the figures 781 mAh / 937 mAh. As you can see, this is 10% more than the previous values.

Third recharge cycle showed slight deviations from previous second recharge. So that’s enough. If you can see that the capacity of your batteries is increasing, you can continue.

repair, electric, screwdriver, battery, home

The battery recovery was able to recover about 8% of the original stated capacity of the electric screwdriver. Not bad in principle, but I would recommend replacing the battery banks with new ones of higher capacity.

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How to Disassemble a Battery

The battery packs of home tools do not differ much in their construction, regardless of the tool model (Bosch, Makita, Hitachi). They are packaged in a two-piece plastic case. The number of batteries can be different, depending on the output voltage of the tool used. All cells are soldered in a specific sequence. The lead ends or terminals where the battery voltage is usually measured are led out.

Most electric screwdriver or drill battery packs are designed so that they are very easy to disassemble, whether we are repairing an Interskol electric screwdriver battery or another model. Several fixing screws should be unscrewed with an ordinary screwdriver. There are some batteries that are difficult to disassemble, but can be removed with a screwdriver and penknife. The adhesive layer is removed with a knife, and a sharp self-tapping screw is used to pull the two mating surfaces apart.

The difference between the batteries of screwdrivers may lie in the presence or absence of the temperature sensor, which automatically shuts down the battery under conditions of critical heating (above 50 ° C). The sensor constantly monitors the temperature not only under load, but also when the battery is currently charged. The controller reads and processes all data, “memorizes” capacity and other indicators. Once the capacity reaches 80-90% and the voltage reaches 14V, the control unit shuts everything down. Such batteries serve for years without losing their technical characteristics.

There are many inexpensive screwdriver models on the market. Cheaper devices do not have these technical devices, and all the processes must be monitored by yourself.

With what to start repairing a faulty battery

The first thing you need to do is to charge the battery, and then open the case, inside of which are the banks. If they are not soldered together, but in the form of an ordinary “AA” battery, it is worth trying to bend the terminals. Sometimes it helps. If not, you have to use a multimeter.

Repair: 12v cordless drill battery replacement

With the switch you need to set the desired voltage (constant) and check each of the banks. If there is no difference, then the problem is in the “memory effect”. A faulty bank will have a much lower charge. It will have to be replaced, although there is a way to try to resurrect the can, provided it is nickel-cadmium, but about this a little later.

It is clear that buying cans is also quite expensive. However, if time is not of the essence for the home maker at the moment, you can order them at Chinese resources. there are much lower, especially if you take batches of 10 pcs. in a package. After all, things like this always come in handy. In addition the nickel-metal hydride cells fit in most laptop batteries, which are also made in a similar way.

How to distinguish a quality screwdriver from a fake: differences in appearance, design, assembly and warranty, tips and recommendations of Homius in the publication.