This is a Circuit that can charge 4 li-ion cells at a time also this can be connected with another PCB and chained to charge upto 20 cells at a time with 1A. It also has A volatge monitor to keep a check on the voltage level. for Cost effectiveness this board uses existing TP4056 modules since the are easily available and also have all teh required protection that are needed..

• Lithium ion battery holder
• TP4056 modules
• 5v 20A Supply for providing enough power to charger the cells
• Voltmeter
• 16 AWG wires for chaining the PCBs
• 2 Fans 8025