Features: Universal USB battery charger with 2 independent charging slots. can charge 2pcs 3.7V 10440/ 14500/ 16340(RCR123A)/ 17335/ 17670/ 18350/ 18500/ 18650 rechargeable lithium batteries at one time. Can identify input voltage and the rechargeable battery quantity intelligently, adjust the charging current automatically. Three-stage charging (TC- CC- CV), with soft-start and over-discharged battery activation functions. Supports over voltage, over current, short circuit and reversed battery protection. With 2 LED indicators, when fully charged, the red indicator light will turn green, and stop charging automatically.