Repair of lithium batteries screwdrivers
This is one of the most difficult types of battery repair, which can end up with nothing. Lithium batteries require special treatment, as their charging program is different from other types of batteries. In short, it is powerfully described in two stages. The first is the supply of DC and voltage to the battery input. As for the current, it is calculated depending on the properties of the battery, but the lower the current, the greater the capacity can be poured into the battery. The voltage in the first stage is constant and equal to the maximum for this type of battery and depends on the number of elements connected in series.
After the voltage reaches the maximum value at the battery contacts, the charger will start to shunt each lithium element to the corresponding resistor. Thus, the so-called balancing of each battery Bank and its overcharging is not allowed.
Balancing Board circuits can be built on transistors and microcontrollers. The first type is most common on the external batteries of various devices, which do not require precise control over the process of charging and the resulting voltage. Microcontrollers are used for intelligent control of the charge process. This allows you to make the downloaded program. In the second case, when repairing the lithium battery, the screwdriver may have a problem. The balance Board on the microcontroller can go into protection mode. This is done to improve the security of this type of device. For example, if a battery or one of its cans is mechanically damaged, the microcontroller fixes the voltage drop and blocks the supply of the input and output voltage of the battery. In this case, the lock can be either software or hardware. If the software lock can still be brought to normal operation, the hardware is treated only by replacing the microcontroller. But it's not all as smooth as you can imagine. For program communication with the balancing Board, appropriate hardware and software are required. Replacing the microcontroller will not help either, in any case, you need a clone of the battery to download the firmware of the microcontroller from it. This is also not always possible to do, as the program can be protected by special fuses.
Here with such problems can be encountered in the repair of lithium batteries screwdrivers, and not only them. Now lithium batteries are firmly included in the consumer segment of household appliances – vacuum cleaners, mixers and other small household appliances. But mostly it uses lithium batteries with a balancing Board built on microcontrollers. Therefore, when you repair, there are many difficulties and without the skill of skill and cunning they are not circumvented.