LM317 Adjustable positive regulator IC with charge circuit current and voltage as Lithium ion batteries can recharge with the limitation. Charging the battery after the charge is dropped, led with cruise altitudes (2-8but) based on the circuit protected defensively... Electronics Projects, 3.6V Lithium Ion Battery Charging Circuit LM317 "battery charger circuit, power electronic projects, simple circuit projects, " Date 2014/06/22