This is a design for a 2 cell lithium ion battery charger and BMS (battery management system). It uses the ip2326 IC to boost the 5v input to 8.4v and charge the battery safely with input/output protection as well as passive balancing. The output of the battery, pads OUT+ and OUT- , will be connected to the load and is protected by the R5460N208A battery monitoring IC. This battery monitoring IC uses two MOSFETs (NTMFS5C430NL) to shut off the output if a fault is detected and will open once the fault is cleared. 

Features 

• Steps 5v input to 8.4V

• Charge indication LED

• 92% boost efficiency (from 5v to 8.4v @ 1.5A)

• PD delivery capability (can ask for more than 5v input)

• Passive Balance charging

• Overvoltage and undervoltage Protection

• Overcharge and Overdischarge Proctection

• Short circuit Protection on input and output

• Input overvoltage and undervoltage protection

• Manual charge current settings (0.5A, 1A, 1.5A)

• 20A max discharge