Intro:

long time i was harvesting lithium ion batteries from scrap laptop battery packs

it's wasn't easy to test battery capacity manually 

so i made this device to tell me the output volt and current of the battery and calculate the battery capacity and life time

Used components :

• display used in this project 1602 LCD with shift register 74ch595 to save atmega328 pins 

• also there is i2c port on the pcb for who wants to add any i2c module but you have to edit the code to fit your needs 

• for charge and discharge i'm using TIP41C isolated by opto coupler 

• inquick test mode the circuit using 2 1 ohms resistors 1 as shunt and the other as load 

• in charge mode using 1 ohm resistor as shunt for current measuring