The working mechanism of two LEDs, red and green, in battery charger

How actually is the working mechanism of two LEDs, red and green, in Li-ion battery charger, it's turned on when no current (open) and when pretty high current (is charging), finally the current gets low because the battery at max volt and full charged then causing the LED turned off and the other, green one, turns on ?

abdulbadii said:

How actually is the working mechanism of two LEDs, red and green, in Li-ion battery charger, it's turned on when no current (open) and when pretty high current (is charging), finally the current gets low because the battery at max volt and full charged then causing the LED turned off and the other, green one, turns on ?

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If you provide a schematic, you may get some answers...

The charger is most likely controlled with a dedicated charge controller chip, which controls the charging and turns on the green LED to indicate full charge.

Different charge controller chips may not behave the same – it depends on how the designers of the chip wanted to do it.

Big Clive on YouTube has examined many different charge controllers and drawn up the circuits used in different devices. His YouTube channel is a good resource to learn more.

You might need to provide source code as well, as it's quite possible it's done in a micro as well.

However, a common small chip used if the TP4056, and the datasheet might help: