How to make a simple charging current indicator for a Li-ion battery

Many radio amateurs use Li-ion batteries from outdated mobile phones, tablets, and MP3 players in their crafts. Such batteries already include a charging controller. Charging them is usually not very convenient, since it is not visually clear whether charging is in progress or the battery is already fully charged.
To solve this problem, you can assemble a simple indicator of the flow of charging current using only 3 parts.

Required Parts

• Chip TC3582DA - http://alii.pub/5lafxm
  
• Pair LEDs - http://alii.pub/5lag4f
  
• Universal mounting plate - http://alii.pub/5lagcs

Circuit of the simplest current indicator

The microcircuit is a current sensor and displays its presence and absence using LEDs. This connection scheme does not require quenching resistors in the circuit LEDs, which is very convenient.
The circuit is connected to the gap between the battery and the charger. When charging current flows, LED1 flashes, and as soon as charging is completed, only LED2 will light up. Everything is elementary simple.

Making a passing current indicator

We take a universal board for installation.

We install the microcircuit into the holes of the board.

Install 2 LED different colors to visually distinguish the process more clearly from afar.

Insert the tinned wires.

We solder the tracks along the board contacts.

Current indicator in operation

We connect the indicator between the 5 V power source and the battery. Red while charging Light-emitting diode flashes.

As soon as charging is completed and current has stopped flowing through the microcircuit, the green LED lights up.

This microcircuit is usually used in universal chargers, popularly called “Frog”.

Watch the video

See how you can make a current indicator without microcircuits on transistors - https://home.washerhouse.com/en/3837-indikator-nalichiya-toka.html