How to restore the screwdriver battery and its capacity? Is it possible to restore the screwdriver battery?

The screwdriver is an important household tool, but the time goes and its energy source – the battery stops working. Models are constantly changing and finding the right battery can sometimes fail. However, you can completely restore it or extend it’s life by 2-3 years. This article tells how to repair a screwdriver battery.

Table of Content:
  • Battery disassembly
  • Substitution of elements
  • Restoring banks
  • How to repair a screwdriver battery
  • “Interskol” screwdriver battery
  • Restoring “Makita” screwdriver battery
  • How to repair a Bosch screwdriver battery
  • Repairing the Hitachi Screwdriver Battery
  • Repairing the Aeg screwdriver battery
  • Battery maintenance tips
  • Conclusion

Battery disassembly

Solving the question of whether it is possible to restore a screwdriver battery, we must first of all understand how to extract elements from it. The battery is housed in a plastic housing of two halves. First, unscrew the connecting screws. If the connection is made by glue, then you have to tinker with a screwdriver or a chisel. Disassemble carefully, so that you would be able to seal the case again. Inside there are elements connected in series. In some designs, a parallel-serial connection is used.

Substitution of elements

Solving the question of how to restore a screwdriver battery, it is necessary, first of all, to identify faulty banks that spoil its work. If the battery is dead, it needs to be charged, and then you should check up the voltage of all elements. It should not differ from the nominal by more than 10%. Repairment here means to restore the battery capacity of the screwdriver generally. It is affected by the health of each element. It must have a specified capacity, which is understood as the ability to feed the load connected to it.

Sometimes it is better to replace the failed components, which get discharge quickly. They can be detected by corrosion damage or the presence of characteristic traces of electrolyte on the surface. One or two elements can be a serious obstacle in the work of the entire line. If the battery is used for more than 3 years, then most of the elements can be faulty. In this case, it is better to replace them all. It is important that they are suitable for voltage and size.

The cost of accumulators assembled separately is lower than the new ones. The serviceability of each bank is checked by the value of the internal resistance, which should be about 0.06 Ohm. To do this, a load is connected to it (a resistor of 5-10 ohms) and at the same time the amperage and voltage are changed. It is convenient to use low voltage incandescent lamps. Measurements are made with two different resistances, 30% and 70% of the permissible load, respectively. From the 1st voltage, the 2nd is subtracted, and from the 2nd amperage — the 1st. Then the results of the subtraction are divided and, in accordance with Ohm’s law, we find the internal resistance of the battery.

The battery is often sold with an extra one. You can assemble one from two and still have the banks left. It is desirable to use them somewhere as power sources, for example, for a flashlight with a car lamp. After the diagnostics, the checked items are connected in a line. The matched kit must be welded in the same order. The bank body has a negative polarity, and the middle bar — positive. Then, without assembling the battery, you need to connect a charger to it. It is necessary to control the temperature of the elements. If they are in service, then there should not be too much overheating.

At the end of the charging time, and also after a day, the voltage of each element should be measured. If any battery is discharged by more than 10%, it needs to be replaced with a new one. After the battery passes the test, you can finish assembling its case. The fastening screws are screwed on the places accordingly to the sizes, and acetate-acrylate (“Super-glue”) is applied as a glue. With a competent selection of items, the battery will serve as a new one. After charging, it should be subjected to intensive training, giving a maximum load to the screwdriver, until it is discharged. Such cycles should be repeated 2 more times, and then – 1 time per quarter.

Restoring banks

Don’t throw away the batteries that failed test. The main reason for their failure is the evaporation of water through a rubber band located between the body and the middle tire. When it is full “zero”, the battery is momentarily charged with a 12V voltage impulse through a resistance of 40-50 ohms. While doing this, you should check that the case does not overheat. If there is still no voltage on it after that, then you can throw it away. To restore the electrolyte, some craftsmen drill mini holes for the syringe needle in the side groove of all battery cells. Then the banks are filled with distilled water. After that the batteries should not be touched for a day. The battery is then “trained”, charged and checked the voltage on each cell. The holes are sealed with silicone.

How to repair a screwdriver battery

All batteries look similar from the inside. They consist of successively welded banks. As a result you get the total battery voltage on the output contacts. The following types of elements are used: Ni-Cd (nickel-cadmium, U = 1.2 V). Ni-MH (nickel-metal-hydride, U = 1.2 V). Li-Ion (lithium-ion, U = 3.6V).

“Interskol” screwdriver battery

Screwdriver “Interskol” is one of the most popular, due to its versatility. In addition to the main function, it can also be used as a drill. You can use any of the common batteries in it. Nickel-cadmium and metal-hydride are used more often, as cheaper and more powerful ones. To ensure that they work reliably, they should be fully discharged and recharged to fully utilize the charge. Otherwise, the life of the equipment is significantly reduced. Reversible loss of capacity of an incompletely discharged and charged element is called a memory effect.

Lithium-ion batteries do not have this disadvantage, but their price is much higher. During the work, when every minute counts, a small charge is often required to maintain the required power of the screwdriver. In this case, these batteries are

indispensable, because their capacity can be quickly restored. The customer selects the battery of the screwdriver “Interskol” on his own, depending on the preferences, capabilities and required work. In most cases, nickel-cadmium batteries are used. How to restore the battery of the screwdriver “Interskol”, if it has not been used for a long time? When operating it is necessary to try to not let the voltage drop down to zero. You can discharge a 1.2V bank up to 0.9V. If the battery is completely discharged during long storage, the charger may not “see” it. It is necessary to “push” the battery with another, more powerful power source, so that a small voltage appears on it. After that, you can connect it to a standard charger.

Restoring “Makita” screwdriver battery

Before you restore the battery of the Makita screwdriver, first you need to disassemble its case. It consists of 2 halves, glued together. If you carefully tap the battery case with a rubber mallet, the adhesive will fall behind. There may be problems with disassembly of some parts. You may need to use additional hand tool. Next, disconnect the halves of the case, holding the screwdriver terminals. According to the performance characteristics, the drill-screwdriver “Makita” is close to the network tool. The autonomous power supply is provided by 2 replaceable Li-Ion batteries. Computer charging technology allows to recover them in just 22 minutes. At the same time, the battery life is significantly increased. Defective banks should be replaced with similar new models. If they are difficult to find on sale, you’ll have to make one of two accumulators. Factory welding can be contact, and during repair it is necessary to create a connection by soldering.

How to repair a Bosch screwdriver battery

Bosch screwdrivers are great for non-professional use. They have accumulators with Ni-Cd elements. They withstand large voltage loads, but quickly self-discharge (during 3-4 weeks). At least once a month they must be restored in order not to fail. In addition, in the process of operation there is an unbalance of the elements and the capacity is lost as time goes by. One of the ways to restore is to disassemble the case and “train” each element separately. If this doesn’t help the way desired, some of them will have to be replaced. Then the battery will last a long time.

Repairing the Hitachi Screwdriver Battery

How to repair a Hitachi screwdriver battery? Both Ni-Cd batteries must be charged, after that they should be disassembled and you should measure the voltage on each bank with a load of 1.5 ohms. Elements showing a lower voltage can be thrown away, and you can make 1 good battery from other good ones. Only 1 or 2 banks can damage the battery. How to restore the battery of the Hitachi screwdriver, as well as all other models, depends, first of all, on the type of elements installed in them.

Repairing the Aeg screwdriver battery

A screwdriver come with 2 batteries in the box. If one of them does not charge, this does not mean it’s broken. It may be discharged too much. In this case, you can try to “train” the battery by applying a pulsed voltage to it, and then put it on charge. The easiest way is to connect to a charged battery for a few seconds. If the recovery of the Aeg screwdriver battery the way described above failed, them its case should be disassembled and each bank checked.

Battery maintenance tips

If the battery has not been used, it should be discharged once a month by the permissible load and recharged again.

It is advisable to buy a screwdriver with two batteries in the kit.

Screwdrivers must be stored and used in conditions that prevent moisture from getting inside.


How to restore a screwdriver battery? There are several ways. Before disassembling it, we must try to find the cause of the malfunction, which can also be a mechanism or a charger problem. Observing the rules of battery operation, stated in the instruction, it is possible to significantly extend its life time.

1 Star2 Stars3 Stars4 Stars5 Stars (1 votes, average: 5.00 of 5)

Related posts:

How to recover Li-Ion battery: a few available tips