2 x TP4056 5V Micro USB 1A 18650 Lithium Battery Charger Module Board – Everything Pi
switch mode power supply - 18650 in series while charging using TP4056 and connecting two buck regulators LM2596 in parallel, is it safe? - Electrical Engineering Stack Exchange
battery charging - Can I Charge 2 18650 with 2 TP4056 boards with single input - Electrical Engineering Stack Exchange