an easy to build charger using cheap and easy to find components.li-ion batteries are very common these days.you can find them everywhere.in laptops,smartphones,e-cigs,etc. in this episode im building a simple charger that can charge 2x18650 type batteries at 1amp each.you can adjust the charge current by replacing a resistor shown in the video.this charger is using the very cheap and popular ic tp4056. you can find a module using this integrated circuit in a few variations, with or without battery protection circuit, with mini or micro usb input, even with type c usb input connector.it can be found everywhere,ali express,e-bay,etc.