What is the black substance on a lithium ion battery chip? Is it harmful to the skin?

If you don't tear the wrapping paper, those are basic copper carbonate, that is, copper raw embroidery substances, harmless! If it is something in the battery, it should be rinsed with plenty of water, but it doesn't matter, the amount is too small.

Is it a piece of black material stuck to the battery? If so, it is not harmful to **, it is the battery manufacturer in order to prevent the battery electrode from short-circuiting and sticking, and it also plays a filling role to make the battery look more beautiful!

Theoretically, yes. Because there is a protective plate on the battery, it will be limited to volts and will no longer be charged. In fact, it is best not to do this, the chemical composition of lithium batteries is very unstable, it is easy to cause ****, usually the battery will also have heating, **, ** situation.

No, the charger will keep charging because it can't be charged.

If it does, your battery will be reimbursed.

The use of lithium batteries in this way is very dangerous and may cause ****.

Yes, that is, most of the chargers are written, and the batteries are generally written.

First of all, it is best to choose a ready-made universal charge for the charging circuit, lithium battery charging requires a constant current source, and constant voltage charging is more damaging to the battery and dangerous

This depends on what is the minimum working voltage and protection voltage of your half-bridge driver chip, but also depends on how much the voltage drop is when you bring full load, first of all, the load increase will definitely pull down the battery voltage, the maximum working voltage of your three strings of lithium battery is 12*6 volts, and the minimum working voltage is about 9 volts, so you can choose a driver chip with a working voltage of 5V, step down the battery voltage to 5V, and supply the driver for use, which can reduce the impact of the voltage drop caused by the load on the drive to a certain extent.

3 strings of lithium-ion batteries have the largest voltage, nominal, whether it depends on the specific datasheet of the chip, such as TL494, the input voltage is generally 18V, the current is no problem, in fact, after starting to work, the chip takes power from the self-powered winding.

What's in there?

Generally, the small battery pack is cut off by the protection board, and Seiko's hardware chip protection board is mostly used to cut off the charging current.

Larger battery packs generally have a management system, which requires the charger to have an intelligent host computer control function and CAN protocol communication.

And the equalization charge and so on!